--- /dev/null
+C-----------------------------------------------------------------------
+C H E R W I G
+C
+C a Monte Carlo event generator for simulating
+C +---------------------------------------------------+
+C | Hadron Emission Reactions With Interfering Gluons |
+C +---------------------------------------------------+
+C I.G. Knowles(*), G. Marchesini(+), M.H. Seymour($) and B.R. Webber(#)
+C-----------------------------------------------------------------------
+C with Minimal Supersymmetric Standard Model Matrix Elements by
+C S. Moretti($) and K. Odagiri($)
+C-----------------------------------------------------------------------
+C R parity violating Supersymmetric Decays and Matrix Elements by
+C P. Richardson(&)
+C-----------------------------------------------------------------------
+C matrix element corrections to top decay and Drell-Yan type processes
+C by G. Corcella(+)
+C-----------------------------------------------------------------------
+C Deep Inelastic Scattering and Heavy Flavour Electroproduction by
+C G. Abbiendi(@) and L. Stanco(%)
+C-----------------------------------------------------------------------
+C and Jet Photoproduction in Lepton-Hadron Collisions by J. Chyla(~)
+C-----------------------------------------------------------------------
+C(*) Department of Physics & Astronomy, University of Edinburgh
+C(+) Dipartimento di Fisica, Universita di Milano
+C($) Rutherford Appleton Laboratory
+C(#) Cavendish Laboratory, Cambridge
+C(&) Department of Physics, University of Oxford
+C(@) Dipartimento di Fisica, Universita di Bologna
+C(%) Dipartimento di Fisica, Universita di Padova
+C(~) Institute of Physics, Prague
+C-----------------------------------------------------------------------
+C Version 6.100 - 16th December 1999
+C-----------------------------------------------------------------------
+C Main reference:
+C G.Marchesini, B.R.Webber, G.Abbiendi, I.G.Knowles, M.H.Seymour,
+C and L.Stanco, Computer Physics Communications 67 (1992) 465.
+C-----------------------------------------------------------------------
+C Please send e-mail about this program to one of the authors at the
+C following Internet addresses:
+C I.Knowles@ed.ac.uk Giuseppe.Marchesini@mi.infn.it
+C M.Seymour@rl.ac.uk webber@hep.phy.cam.ac.uk
+C-----------------------------------------------------------------------
+CDECK ID>, DECADD.
+*CMZ :- -28/01/92 12.34.44 by Mike Seymour
+*-- Author : Luca Stanco
+C-----------------------------------------------------------------------
+ SUBROUTINE DECADD(LOGI)
+C-----------------------------------------------------------------------
+C DUMMY SUBROUTINE: DELETE AND SET BDECAY='CLEO'
+C IN MAIN PROGRAM IF YOU USE CLEO DECAY PACKAGE
+C-----------------------------------------------------------------------
+ LOGICAL LOGI
+ WRITE (6,10)
+ 10 FORMAT(/10X,'DECADD CALLED BUT NOT LINKED')
+ STOP
+ END
+CDECK ID>, EUDINI.
+*CMZ :- -28/01/92 12.34.44 by Mike Seymour
+*-- Author : Luca Stanco
+C-----------------------------------------------------------------------
+ SUBROUTINE EUDINI
+C-----------------------------------------------------------------------
+C DUMMY SUBROUTINE: DELETE AND SET BDECAY='EURO'
+C IN MAIN PROGRAM IF YOU USE EURODEC DECAY PACKAGE
+C-----------------------------------------------------------------------
+ WRITE (6,10)
+ 10 FORMAT(/10X,'EUDINI CALLED BUT NOT LINKED')
+ STOP
+ END
+CDECK ID>, FRAGMT.
+*CMZ :- -28/01/92 12.34.44 by Mike Seymour
+*-- Author : Luca Stanco
+C-----------------------------------------------------------------------
+ SUBROUTINE FRAGMT(I,J,K)
+C-----------------------------------------------------------------------
+C DUMMY SUBROUTINE: DELETE AND SET BDECAY='EURO'
+C IN MAIN PROGRAM IF YOU USE EURODEC DECAY PACKAGE
+C-----------------------------------------------------------------------
+ INTEGER I,J,K
+ WRITE (6,10)
+ 10 FORMAT(/10X,'FRAGMT CALLED BUT NOT LINKED')
+ STOP
+ END
+CDECK ID>, HVCBVI.
+*CMZ :- -28/01/92 12.34.44 by Mike Seymour
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HVCBVI
+C-----------------------------------------------------------------------
+C DUMMY ROUTINE: DELETE IF YOU LINK TO BARYON NUMBER VIOLATN PACKAGE
+C-----------------------------------------------------------------------
+ WRITE (6,10)
+ 10 FORMAT(/10X,'HVCBVI CALLED BUT NOT LINKED')
+ STOP
+ END
+CDECK ID>, HVHBVI.
+*CMZ :- -28/01/92 12.34.44 by Mike Seymour
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HVHBVI
+C-----------------------------------------------------------------------
+C DUMMY ROUTINE: DELETE IF YOU LINK TO BARYON NUMBER VIOLATN PACKAGE
+C-----------------------------------------------------------------------
+ WRITE (6,10)
+ 10 FORMAT(/10X,'HERBVI CALLED BUT NOT LINKED')
+ STOP
+ END
+CDECK ID>, HWBAZF.
+*CMZ :- -26/04/91 11.11.54 by Bryan Webber
+*-- Author : Ian Knowles
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBAZF(IPAR,JPAR,VEC1,VEC2,VEC3,VEC)
+C-----------------------------------------------------------------------
+C Azimuthal correlation functions for Collins' algorithm,
+C see I.G.Knowles, Comp. Phys. Comm. 58 (90) 271 for notation.
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION Z1,Z2,DOT12,DOT23,DOT31,TR,FN(7),VEC1(2),VEC2(2),
+ & VEC3(2),VEC(2)
+ INTEGER IPAR,JPAR
+ LOGICAL GLUI,GLUJ
+ IF (.NOT.AZSPIN) RETURN
+ Z1=PPAR(4,JPAR)/PPAR(4,IPAR)
+ Z2=1.-Z1
+ GLUI=IDPAR(IPAR).EQ.13
+ GLUJ=IDPAR(JPAR).EQ.13
+ IF (GLUI) THEN
+ IF (GLUJ) THEN
+C Branching: g--->gg
+ FN(2)=Z2/Z1
+ FN(3)=1./FN(2)
+ FN(4)=Z1*Z2
+ FN(1)=FN(2)+FN(3)+FN(4)
+ FN(5)=FN(2)+2.*Z1
+ FN(6)=FN(3)+2.*Z2
+ FN(7)=FN(4)-2.
+ ELSE
+C Branching: g--->qqbar
+ FN(1)=(Z1*Z1+Z2*Z2)/2.
+ FN(2)=0.
+ FN(3)=0.
+ FN(4)=-Z1*Z2
+ FN(5)=-(2.*Z1-1.)/2.
+ FN(6)=-FN(5)
+ FN(7)=FN(1)
+ ENDIF
+ ELSE
+ IF (GLUJ) THEN
+C Branching: q--->gq
+ FN(1)=(1.+Z2*Z2)/(2.*Z1)
+ FN(2)=Z2/Z1
+ FN(3)=0.
+ FN(4)=0.
+ FN(5)=FN(1)
+ FN(6)=(1.+Z2)/2.
+ FN(7)=-FN(6)
+ ELSE
+C Branching: q--->qg
+ FN(1)=(1.+Z1*Z1)/(2.*Z2)
+ FN(2)=0.
+ FN(3)=Z1/Z2
+ FN(4)=0.
+ FN(5)=(1.+Z1)/2.
+ FN(6)=FN(1)
+ FN(7)=-FN(5)
+ ENDIF
+ ENDIF
+ DOT12=VEC1(1)*VEC2(1)+VEC1(2)*VEC2(2)
+ DOT23=VEC2(1)*VEC3(1)+VEC2(2)*VEC3(2)
+ DOT31=VEC3(1)*VEC1(1)+VEC3(2)*VEC1(2)
+ TR=1./(FN(1)+FN(2)*DOT23+FN(3)*DOT31+FN(4)*DOT12)
+ VEC(1)=((FN(2)+FN(5)*DOT23)*VEC1(1)
+ & +(FN(3)+FN(6)*DOT31)*VEC2(1)
+ & +(FN(4)+FN(7)*DOT12)*VEC3(1))*TR
+ VEC(2)=((FN(2)+FN(5)*DOT23)*VEC1(2)
+ & +(FN(3)+FN(6)*DOT31)*VEC2(2)
+ & +(FN(4)+FN(7)*DOT12)*VEC3(2))*TR
+ END
+CDECK ID>, HWBCON.
+*CMZ :- -26/04/91 10.18.56 by Bryan Webber
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBCON
+C-----------------------------------------------------------------------
+C MAKES COLOUR CONNECTIONS BETWEEN JETS
+C MODIFIED 12/10/97 BY BRW FOR SUSY PROCESSES
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER IHEP,IST,ID,JC,KC,JD,JHEP,LHEP,ID2
+ IF (IERROR.NE.0) RETURN
+ IF(.NOT.RPARTY) THEN
+ CALL HWBRCN
+ RETURN
+ ENDIF
+ DO 20 IHEP=1,NHEP
+ IST=ISTHEP(IHEP)
+C---LOOK FOR PARTONS WITHOUT COLOUR MOTHERS
+ IF (IST.LT.145.OR.IST.GT.152) GOTO 20
+ IF (JMOHEP(2,IHEP).EQ.0) THEN
+C---FIND COLOUR-CONNECTED PARTON
+ JC=JMOHEP(1,IHEP)
+ IF (IST.NE.152) JC=JMOHEP(1,JC)
+ JC =JMOHEP(2,JC)
+ IF (JC.EQ.0) CALL HWWARN('HWBCON',51,*20)
+C---FIND SPECTATOR WHEN JC IS DECAYED HEAVY QUARK OR SUSY PARTICLE
+ IF (ISTHEP(JC).EQ.155) THEN
+ IF (IDHEP(JMOHEP(1,JC)).EQ.94) THEN
+C---DECAYED BEFORE HADRONIZING
+ JHEP=JMOHEP(2,JC)
+ IF (JHEP.EQ.0) GO TO 20
+ ID=IDHW(JHEP)
+ IF (ISTHEP(JHEP).EQ.155) THEN
+C---SPECIAL FOR GLUINO DECAYS
+ IF (ID.EQ.449) THEN
+ ID=IDHW(JC)
+C---N.B. WILL NEED MODS WHEN SUSY PARTICLES CAN SHOWER
+ IF (ID.EQ.449.OR.ID.EQ.13.OR.
+ & (ID.GE.401.AND.ID.LE.406).OR.
+ & (ID.GE.413.AND.ID.LE.418).OR.
+ & ID.LE.6.OR.(ID.GE.115.AND.ID.LE.120)) THEN
+C---LOOK FOR ANTI(S)QUARK OR GLUON
+ DO KC=JDAHEP(1,JHEP),JDAHEP(2,JHEP)
+ ID=IDHW(KC)
+ IF ((ID.GE. 7.AND.ID.LE. 13).OR.
+ & (ID.GE.407.AND.ID.LE.412).OR.
+ & (ID.GE.419.AND.ID.LE.424)) GOTO 5
+ ENDDO
+ ELSE
+C---LOOK FOR (S)QUARK OR GLUON
+ DO KC=JDAHEP(1,JHEP),JDAHEP(2,JHEP)
+ ID=IDHW(KC)
+ IF (ID.LE. 6.OR. ID.EQ. 13.OR.
+ & (ID.GE.401.AND.ID.LE.406).OR.
+ & (ID.GE.413.AND.ID.LE.418)) GOTO 5
+ ENDDO
+ ENDIF
+C---COULDNT FIND ONE
+ CALL HWWARN('HWBCON',101,*999)
+ 5 JC=KC
+ ELSE
+C--PR MOD 30/6/99 should fix HWCFOR 104 errors
+ ID2 = IDHW(IHEP)
+ IF(IDHW(JDAHEP(1,JHEP)).EQ.449.AND.
+ & (ID2.LE.6.OR.(ID2.GE.115.AND.ID2.LE.120).OR.
+ & (ID2.GE.401.AND.ID2.LE.406).OR.ID2.EQ.13.OR.
+ & (ID2.GE.413.AND.ID2.LE.418).OR.ID2.EQ.449)) THEN
+ JC = JDAHEP(1,JHEP)
+ ELSE
+ JC=JDAHEP(2,JHEP)
+ ENDIF
+ ENDIF
+ ELSEIF (ID.EQ.6.OR.ID.EQ.12.OR.
+ & (ID.GE.209.AND.ID.LE.218).OR.
+ & (ID.GE.401.AND.ID.LE.424).OR.ID.EQ.449) THEN
+C Wait for partner heavy quark to decay
+C RETURN
+C---N.B. MAY BE A PROBLEM HERE
+ GOTO 20
+ ELSE
+ JMOHEP(2,IHEP)=JHEP
+ JDAHEP(2,JHEP)=IHEP
+ GOTO 20
+ ENDIF
+ ELSE
+ JC=JMOHEP(2,JC)
+ ENDIF
+ ENDIF
+ JC=JDAHEP(1,JC)
+ JD=JDAHEP(2,JC)
+C---SEARCH IN CORRESPONDING JET
+ IF (JD.LT.JC) JD=JC
+ LHEP=0
+ DO 10 JHEP=JC,JD
+ IF (ISTHEP(JHEP).LT.145.OR.ISTHEP(JHEP).GT.152) GOTO 10
+ IF (JDAHEP(2,JHEP).EQ.IHEP) LHEP=JHEP
+ IF (JDAHEP(2,JHEP).NE.0) GOTO 10
+C---JOIN IHEP AND JHEP
+ JMOHEP(2,IHEP)=JHEP
+ JDAHEP(2,JHEP)=IHEP
+ GOTO 20
+ 10 CONTINUE
+ IF (LHEP.NE.0) THEN
+ JMOHEP(2,IHEP)=LHEP
+C ELSE
+C---DIDN'T FIND PARTNER OF IHEP YET
+C CALL HWWARN('HWBCON',52,*20)
+ ENDIF
+ ENDIF
+ 20 CONTINUE
+C---BREAK COLOUR CONNECTIONS WITH PHOTONS
+ IHEP=1
+ 30 IF (IHEP.LE.NHEP) THEN
+ IF (IDHW(IHEP).EQ.59 .AND. ISTHEP(IHEP).EQ.149) THEN
+C BRW FIX 13/03/99
+ IF (JMOHEP(2,IHEP).NE.0) THEN
+ IF (JDAHEP(2,JMOHEP(2,IHEP)).EQ.IHEP)
+ & JDAHEP(2,JMOHEP(2,IHEP))=JDAHEP(2,IHEP)
+ ENDIF
+C END FIX
+ IF (JDAHEP(2,IHEP).NE.0) THEN
+ IF (JMOHEP(2,JDAHEP(2,IHEP)).EQ.IHEP)
+ & JMOHEP(2,JDAHEP(2,IHEP))=JMOHEP(2,IHEP)
+ ENDIF
+ JMOHEP(2,IHEP)=IHEP
+ JDAHEP(2,IHEP)=IHEP
+ ENDIF
+ IHEP=IHEP+1
+ GOTO 30
+ ENDIF
+ 999 END
+CDECK ID>, HWBDED.
+*CMZ :- -22/04/96 13.54.08 by Mike Seymour
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBDED(IOPT)
+C FILL MISSING AREA OF DALITZ PLOT WITH 3-JET AND 2-JET+GAMMA EVENTS
+C IF (IOPT.EQ.1) SET UP EVENT RECORD
+C IF (IOPT.EQ.2) CLEAN UP EVENT RECORD AFTER SHOWERING
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWBVMC,HWR,HWUALF,HWUSQR,X(3),W,WMAX,WSUM,
+ & X1MIN,X1MAX,X2MIN,X2MAX,QSCALE,GAMFAC,GLUFAC,R(3,3),CS,SN,M(3),
+ & E(3),LAMBDA,A,B,C,PTSQ,EM,P1(5),P2(5),PVRT(4),EPS,MASDEP
+ INTEGER ID,ID3,EMIT,NOEMIT,IEVT,IHEP,JHEP,KHEP,ICMF,IOPT,IEDT(3),
+ & I,NDEL
+ EXTERNAL HWBVMC,HWR,HWUALF,HWUSQR
+ SAVE X,WMAX
+ DATA WSUM,WMAX,X1MIN,X1MAX,EMIT,ICMF,IEVT
+ & /0.994651,1.84096,0,0.773459,3*0/
+ LAMBDA(A,B,C)=(A**2+B**2+C**2-2*A*B-2*B*C-2*C*A)/(4*A)
+ IF (IOPT.EQ.1) THEN
+C---FIND AN UNTREATED CMF
+ IF (IEVT.EQ.NEVHEP+NWGTS) RETURN
+ IEVT=0
+ ICMF=0
+ DO 10 IHEP=1,NHEP
+ 10 IF (ICMF.EQ.0 .AND. ISTHEP(IHEP).EQ.110 .AND.
+ & JDAHEP(2,IHEP).EQ.JDAHEP(1,IHEP)+1) ICMF=IHEP
+ IF (ICMF.EQ.0) RETURN
+ EM=PHEP(5,ICMF)
+ IF (EM.LT.2*HWBVMC(1)) RETURN
+C---GENERATE X1,X2 ACCORDING TO 1/((1-X1)*(1-X2))
+ 100 CONTINUE
+C---CHOOSE X1
+ X(1)=1-(1-X1MAX)*((1-X1MIN)/(1-X1MAX))**HWR()
+C---CHOOSE X2
+ X2MIN=MAX(X(1),1-X(1))
+ X2MAX=(4*X(1)-3+2*REAL( CMPLX( X(1)**3+135*(X(1)-1)**3,
+ & 3*HWUSQR(3*(128*X(1)**4-368*X(1)**3+405*X(1)**2-216*X(1)+54))*
+ & (X(1)-1) )**(1./3) ))/3
+ IF (X2MAX.GE.ONE.OR.X2MIN.GE.ONE.OR.X2MAX.LE.X2MIN) GOTO 100
+ X(2)=1-(1-X2MAX)*((1-X2MIN)/(1-X2MAX))**HWR()
+C---CALCULATE WEIGHT
+ W=2 * LOG((1-X1MIN)/(1-X1MAX))*LOG((1-X2MIN)/(1-X2MAX)) *
+ & (X(1)**2+X(2)**2)
+C---GENERATE UNWEIGHTED (X1,X2) PAIRS (EFFICIENCY IS ~50%)
+ IF (WMAX*HWR().GT.W) GOTO 100
+C---SYMMETRIZE X1,X2
+ X(3)=2-X(1)-X(2)
+ IF (HWR().GT.HALF) THEN
+ X(1)=X(2)
+ X(2)=2-X(3)-X(1)
+ ENDIF
+C---CHOOSE WHICH PARTON WILL EMIT
+ EMIT=1
+ IF (HWR().LT.X(1)**2/(X(1)**2+X(2)**2)) EMIT=2
+ NOEMIT=3-EMIT
+ IHEP=JDAHEP( EMIT,ICMF)
+ JHEP=JDAHEP(NOEMIT,ICMF)
+C---PREFACTORS FOR GAMMA AND GLUON CASES
+ QSCALE=HWUSQR((1-X(1))*(1-X(2))*(1-X(3)))*EM/X(NOEMIT)
+ ID=IDHW(JDAHEP(1,ICMF))
+ GAMFAC=ALPFAC*ALPHEM*ICHRG(ID)**2/(18*PIFAC)
+ GLUFAC=0
+ IF (QSCALE.GT.HWBVMC(13))
+ & GLUFAC=CFFAC/(2*PIFAC)*HWUALF(1,QSCALE)
+C---IN FRACTION FAC*WSUM OF EVENTS ADD A GAMMA/GLUON
+ IF (GAMFAC*WSUM .GT. HWR()) THEN
+ ID3=59
+ ELSEIF (GLUFAC*WSUM .GT. HWR()) THEN
+ ID3=13
+ ELSE
+ EMIT=0
+ RETURN
+ ENDIF
+C---CHECK INFRA-RED CUT-OFF FOR GAMMA/GLUON
+ M(1)=HWBVMC(ID)
+ M(2)=HWBVMC(ID)
+ M(3)=HWBVMC(ID3)
+ E(1)=HALF*EM*(X(1)+(M(1)**2-M(2)**2-M(3)**2)/EM**2)
+ E(2)=HALF*EM*(X(2)+(M(2)**2-M(3)**2-M(1)**2)/EM**2)
+ E(3)=EM-E(1)-E(2)
+ PTSQ=-LAMBDA(E(NOEMIT)**2-M(NOEMIT)**2,E(3)**2-M(3)**2,
+ & E(EMIT)**2-M(EMIT)**2)
+ IF (PTSQ.LE.ZERO .OR.
+ $ E(1).LE.M(1).OR.E(2).LE.M(2).OR.E(3).LE.M(3)) THEN
+ EMIT=0
+ RETURN
+ ENDIF
+C---CALCULATE MASS-DEPENDENT SUPRESSION
+ IF (MOD(IPROC,10).GT.0) THEN
+ EPS=(RMASS(ID)/EM)**2
+ MASDEP=X(1)**2+X(2)**2
+ $ -4*EPS*X(3)-2*EPS*((1-X(2))/(1-X(1))+(1-X(1))/(1-X(2)))
+ $ -4*EPS**2*X(3)**2/((1-X(1))*(1-X(2)))
+ IF (MASDEP.LT.HWR()*(X(1)**2+X(2)**2)) THEN
+ EMIT=0
+ RETURN
+ ENDIF
+ ENDIF
+C---STORE OLD MOMENTA
+ CALL HWVEQU(5,PHEP(1,JDAHEP(1,ICMF)),P1)
+ CALL HWVEQU(5,PHEP(1,JDAHEP(2,ICMF)),P2)
+C---GET THE NON-EMITTING PARTON'S CMF DIRECTION
+ CALL HWULOF(PHEP(1,ICMF),PHEP(1,JHEP),PHEP(1,JHEP))
+ CALL HWRAZM(ONE,CS,SN)
+ CALL HWUROT(PHEP(1,JHEP),CS,SN,R)
+ M(1)=PHEP(5,IHEP)
+ M(2)=PHEP(5,JHEP)
+ M(3)=RMASS(ID3)
+C---REORDER ENTRIES: IHEP=EMITTER, JHEP=NON-EMITTER, KHEP=EMITTED
+ NHEP=NHEP+1
+ IF (IDHW(IHEP).LT.IDHW(JHEP)) THEN
+ IHEP=JDAHEP(1,ICMF)
+ JHEP=NHEP
+ ELSE
+ IHEP=NHEP
+ JHEP=JDAHEP(1,ICMF)
+ ENDIF
+ KHEP=JDAHEP(2,ICMF)
+C---SET UP MOMENTA
+ PHEP(5,JHEP)=M(NOEMIT)
+ PHEP(5,IHEP)=M(EMIT)
+ PHEP(5,KHEP)=M(3)
+ PHEP(4,JHEP)=HALF*EM*(X(NOEMIT)+
+ & (M(NOEMIT)**2-M(EMIT)**2-M(3)**2)/EM**2)
+ PHEP(4,IHEP)=HALF*EM*(X(EMIT)+
+ & (M(EMIT)**2-M(NOEMIT)**2-M(3)**2)/EM**2)
+ PHEP(4,KHEP)=EM-PHEP(4,IHEP)-PHEP(4,JHEP)
+ PHEP(3,JHEP)=HWUSQR(PHEP(4,JHEP)**2-PHEP(5,JHEP)**2)
+ PHEP(3,IHEP)=( (PHEP(4,KHEP)**2-PHEP(5,KHEP)**2) -
+ & (PHEP(4,IHEP)**2-PHEP(5,IHEP)**2) -
+ & (PHEP(3,JHEP)**2) )*HALF/PHEP(3,JHEP)
+ PHEP(3,KHEP)=-PHEP(3,IHEP)-PHEP(3,JHEP)
+ PHEP(2,JHEP)=0
+ PHEP(2,IHEP)=0
+ PHEP(2,KHEP)=0
+ PHEP(1,JHEP)=0
+ PHEP(1,IHEP)=HWUSQR(PHEP(4,IHEP)**2-
+ & PHEP(3,IHEP)**2-PHEP(5,IHEP)**2)
+ PHEP(1,KHEP)=-PHEP(1,IHEP)
+C---ORIENT IN CMF, THEN BOOST TO LAB
+ CALL HWUROB(R,PHEP(1,IHEP),PHEP(1,IHEP))
+ CALL HWUROB(R,PHEP(1,JHEP),PHEP(1,JHEP))
+ CALL HWUROB(R,PHEP(1,KHEP),PHEP(1,KHEP))
+ CALL HWULOB(PHEP(1,ICMF),PHEP(1,IHEP),PHEP(1,IHEP))
+ CALL HWULOB(PHEP(1,ICMF),PHEP(1,JHEP),PHEP(1,JHEP))
+ CALL HWULOB(PHEP(1,ICMF),PHEP(1,KHEP),PHEP(1,KHEP))
+C---CALCULATE PRODUCTION VERTICES
+ CALL HWVZRO(4,VHEP(1,JHEP))
+ CALL HWVSUM(4,PHEP(1,IHEP),PHEP(1,KHEP),PVRT)
+ CALL HWUDKL(ID,PVRT,VHEP(1,KHEP))
+ CALL HWVEQU(4,VHEP(1,KHEP),VHEP(1,IHEP))
+C---REORDER ENTRIES: IHEP=QUARK, JHEP=ANTI-QUARK, KHEP=EMITTED
+ IF (IHEP.EQ.NHEP) THEN
+ IHEP=JHEP
+ JHEP=NHEP
+ ENDIF
+C---STATUS, ID AND POINTERS
+ ISTHEP(JHEP)=114
+ IDHW(JHEP)=IDHW(KHEP)
+ IDHEP(JHEP)=IDHEP(KHEP)
+ IDHW(KHEP)=ID3
+ IDHEP(KHEP)=IDPDG(ID3)
+ JDAHEP(2,ICMF)=JHEP
+ JMOHEP(1,JHEP)=ICMF
+ JDAHEP(1,JHEP)=0
+C---COLOUR CONNECTIONS AND GLUON POLARIZATION
+ JMOHEP(2,JHEP)=IHEP
+ JDAHEP(2,IHEP)=JHEP
+ IF (ID3.EQ.13) THEN
+ JMOHEP(2,IHEP)=KHEP
+ JMOHEP(2,KHEP)=JHEP
+ JDAHEP(2,JHEP)=KHEP
+ JDAHEP(2,KHEP)=IHEP
+ GPOLN=((1-X(1))**2+(1-X(2))**2)/(4*(1-X(3)))
+ GPOLN=1/(1+GPOLN)
+ ELSE
+ JMOHEP(2,IHEP)=JHEP
+ JMOHEP(2,KHEP)=KHEP
+ JDAHEP(2,JHEP)=IHEP
+ JDAHEP(2,KHEP)=KHEP
+ ENDIF
+ IEVT=NEVHEP+NWGTS
+ ELSEIF (IOPT.EQ.2) THEN
+C---MAKE THREE-JET EVENTS FROM THE `DEAD-ZONE' LOOK LIKE TWO-JET EVENTS
+ IF (EMIT.EQ.0.OR.IEVT.NE.NEVHEP+NWGTS) THEN
+ RETURN
+ ELSEIF (EMIT.EQ.1) THEN
+ IHEP=JDAHEP(1,JDAHEP(1,ICMF)+1)
+ JHEP=JDAHEP(1,JDAHEP(1,ICMF))
+ ELSE
+ IHEP=JDAHEP(1,JDAHEP(2,ICMF))
+ JHEP=JDAHEP(1,JDAHEP(1,ICMF)+1)
+ JDAHEP(1,JDAHEP(2,ICMF))=JHEP
+ IDHW(JHEP)=IDHW(IHEP)
+ IF (ISTHEP(IHEP+1).EQ.100 .AND. ISTHEP(JHEP+1).EQ.100)
+ & CALL HWVEQU(5,PHEP(1,IHEP+1),PHEP(1,JHEP+1))
+ ENDIF
+ JMOHEP(2,JDAHEP(1,ICMF))=JDAHEP(2,ICMF)
+ JDAHEP(2,JDAHEP(1,ICMF))=JDAHEP(2,ICMF)
+ JMOHEP(2,JDAHEP(2,ICMF))=JDAHEP(1,ICMF)
+ JDAHEP(2,JDAHEP(2,ICMF))=JDAHEP(1,ICMF)
+ CALL HWVEQU(5,P1,PHEP(1,JDAHEP(1,ICMF)))
+ CALL HWVEQU(5,P2,PHEP(1,JDAHEP(2,ICMF)))
+ CALL HWVSUM(4,PHEP(1,IHEP),PHEP(1,JHEP),PHEP(1,JHEP))
+ CALL HWUMAS(PHEP(1,JHEP))
+ JDAHEP(2,JHEP)=JDAHEP(2,IHEP)
+ IEDT(1)=JDAHEP(1,ICMF)+1
+ IEDT(2)=IHEP
+ IEDT(3)=IHEP+1
+ NDEL=3
+ IF (ISTHEP(IHEP+1).NE.100) NDEL=2
+ CALL HWUEDT(NDEL,IEDT)
+ DO 410 I=1,2
+ IHEP=JDAHEP(1,JDAHEP(I,ICMF))
+ JMOHEP(1,IHEP)=JDAHEP(I,ICMF)
+ IF (ISTHEP(IHEP+1).EQ.100) THEN
+ JMOHEP(1,IHEP+1)=JMOHEP(1,IHEP)
+ JMOHEP(2,IHEP+1)=JMOHEP(2,JMOHEP(1,IHEP))
+ ENDIF
+ DO 400 JHEP=JDAHEP(1,IHEP),JDAHEP(2,IHEP)
+ JMOHEP(1,JHEP)=IHEP
+ 400 CONTINUE
+ CALL HWVZRO(4,VHEP(1,JDAHEP(I,ICMF)))
+ CALL HWVZRO(4,VHEP(1,IHEP))
+ IF (ISTHEP(IHEP+1).EQ.100) CALL HWVZRO(4,VHEP(1,IHEP+1))
+ 410 CONTINUE
+ EMIT=0
+ IEVT=0
+ ELSE
+ CALL HWWARN('HWBDED',500,*999)
+ ENDIF
+ 999 END
+CDECK ID>, HWBDIS.
+*CMZ :- -17/05/94 09.33.08 by Mike Seymour
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBDIS(IOPT)
+C-----------------------------------------------------------------------
+C FILL MISSING AREA OF DIS PHASE-SPACE WITH 2+1-JET EVENTS
+C IF (IOPT.EQ.1) SET UP EVENT RECORD
+C IF (IOPT.EQ.2) CLEAN UP EVENT RECORD AFTER SHOWERING
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWR,HWBVMC,HWUALF,HWULDO,P1(5),P2(5),P3(5),
+ & PCMF(5),L(5),R(3,3),Q,XBJ,RN,XPMIN,XPMAX,XP,ZPMIN,ZPMAX,ZP,FAC,
+ & X1,X2,XTSQ,XT,PTSQ,SIN1,SIN2,W1,W2,CFAC,PDFOLD(13),PDFNEW(13),
+ & PHI,SCALE,Q1(5),Q2(5),DIR1,DIR2,DIR,PM(5),POLD,PNEW,COMINT,
+ & BGFINT,COMWGT,C1,C2,CM,B1,B2,BM,PVRT(4)
+ INTEGER IOPT,EMIT,ICMF,IHEP,JHEP,IIN,IOUT,ILEP,IHAD,ID,IDNEW,
+ & IEDT(3),NDEL,NTRY,ITEMP
+ LOGICAL BGF
+ EXTERNAL HWR,HWBVMC,HWUALF,HWULDO
+ SAVE BGF,IIN,IOUT,ICMF,ID,Q1,Q2,XP,XBJ
+ DATA EMIT,COMINT,BGFINT,COMWGT/0,3.9827,1.2462,0.3/
+ DATA C1,C2,CM,B1,B2,BM/0.56,0.20,10,0.667,0.167,3/
+ IF (IERROR.NE.0) RETURN
+ IF (IOPT.EQ.1) THEN
+C---FIND AN UNTREATED CMF
+ IF (EMIT.EQ.NEVHEP+NWGTS) RETURN
+ ICMF=0
+ DO 10 IHEP=1,NHEP
+ 10 IF (ICMF.EQ.0 .AND. ISTHEP(IHEP).EQ.110 .AND.
+ & JDAHEP(2,IHEP).EQ.JDAHEP(1,IHEP)+1) ICMF=IHEP
+ IF (ICMF.EQ.0) RETURN
+ IIN=JMOHEP(2,ICMF)
+ IOUT=JDAHEP(2,ICMF)
+ ILEP=JMOHEP(1,ICMF)
+ CALL HWVEQU(5,PHEP(1,IIN),P1)
+ CALL HWVEQU(5,PHEP(1,IOUT),P2)
+ CALL HWVEQU(5,PHEP(1,ILEP),L)
+ IHAD=2
+ IF (JDAHEP(1,IHAD).NE.0) IHAD=JDAHEP(1,IHAD)
+ ID=IDHW(IIN)
+C---STORE OLD MOMENTA
+ CALL HWVEQU(5,P1,Q1)
+ CALL HWVEQU(5,P2,Q2)
+C---BOOST AND ROTATE THE MOMENTA TO THE BREIT FRAME
+ CALL HWVDIF(4,P2,P1,PCMF)
+ CALL HWUMAS(PCMF)
+ CALL HWVEQU(5,PHEP(1,IHAD),PM)
+ Q=-PCMF(5)
+ XBJ=HALF*Q**2/HWULDO(PM,PCMF)
+ CALL HWVSCA(4,HALF/XBJ,PCMF,PCMF)
+ CALL HWVSUM(4,PM,PCMF,PCMF)
+ CALL HWUMAS(PCMF)
+ CALL HWULOF(PCMF,L,L)
+ CALL HWULOF(PCMF,PM,PM)
+ CALL HWUROT(PM,ONE,ZERO,R)
+ CALL HWUROF(R,L,L)
+ PHI=ATAN2(L(2),L(1))
+ CALL HWUROT(PM,COS(PHI),SIN(PHI),R)
+C---CHOOSE THE HADRONIC-PLANE CONFIGURATION, XP,ZP
+ IF (HWR().LT.COMWGT) THEN
+C-----CONSIDER GENERATING A QCD COMPTON EVENT
+ BGF=.FALSE.
+ P3(5)=RMASS(13)
+ 100 RN=HWR()
+ IF (RN.LT.C1) THEN
+ ZP=HWR()
+ XPMAX=MIN(ZP,1-ZP)
+ XP=HWR()*XPMAX
+ FAC=1/C1*2*XPMAX/((1-XP)*(1-ZP))*
+ $ (1+(1-XP-ZP+2*XP*ZP)**2+2*(1-XP)*(1-ZP)*XP*ZP)
+ IF (HWR().LT.HALF) THEN
+ ZPMAX=ZP
+ ZP=XP
+ XP=ZPMAX
+ ENDIF
+ ELSEIF (RN.LT.C1+C2) THEN
+ XPMAX=0.83
+ XP=XPMAX*HWR()
+ ZPMIN=MAX(XP,1-XP)
+ ZPMAX=1-2./3.*XP*(1+REAL( CMPLX(10-45*XP+18*XP**2,3*SQRT(
+ $ 3*(9+66*XP-93*XP**2+12*XP**3-8*XP**4+24*XP**5-8*XP**6)))
+ $ **(1./3.) * CMPLX(0.5,0.8660254) ))
+ ZP=1-((1-ZPMIN)/(1-ZPMAX))**HWR()*(1-ZPMAX)
+ FAC=1/C2*XPMAX*LOG((1-ZPMIN)/(1-ZPMAX))/(1-XP)*
+ $ (1+(1-XP-ZP+2*XP*ZP)**2+2*(1-XP)*(1-ZP)*XP*ZP)
+ ELSE
+ ZPMAX=0.85
+ ZP=ZPMAX*HWR()
+ XPMIN=MAX(ZP,1-ZP)
+ XPMAX=(1+4*ZP*(1-ZP))/(1+6*ZP*(1-ZP))
+ XP=1-((1-XPMIN)/(1-XPMAX))**HWR()*(1-XPMAX)
+ FAC=1/(1-C1-C2)*ZPMAX*LOG((1-XPMIN)/(1-XPMAX))/(1-ZP)*
+ $ (1+(1-XP-ZP+2*XP*ZP)**2+2*(1-XP)*(1-ZP)*XP*ZP)
+ ENDIF
+ XPMAX=(1+4*ZP*(1-ZP))/(1+6*ZP*(1-ZP))
+ ZPMAX=1-2./3.*XP*(1+REAL( CMPLX(10-45*XP+18*XP**2,3*SQRT(
+ $ 3*(9+66*XP-93*XP**2+12*XP**3-8*XP**4+24*XP**5-8*XP**6)))
+ $ **(1./3.) * CMPLX(0.5,0.8660254) ))
+ IF (XP.GT.XPMAX.OR.ZP.GT.ZPMAX.OR.CM*HWR().GT.FAC)
+ $ GOTO 100
+ ELSE
+C-----CONSIDER GENERATING A BGF EVENT
+ BGF=.TRUE.
+ P3(5)=P1(5)
+ P1(5)=RMASS(13)
+ 110 RN=HWR()
+ IF (RN.LT.B1) THEN
+ ZP=HWR()
+ XPMAX=MIN(ZP,1-ZP)
+ XP=HWR()*XPMAX
+ FAC=1/B1*2*XPMAX/(1-ZP)*
+ $ (( XP+ZP-2*XP*ZP)**2+2*(1-XP)*(1-ZP)*XP*ZP
+ $ +(1-XP-ZP+2*XP*ZP)**2+2*(1-XP)*(1-ZP)*XP*ZP)
+ IF (HWR().LT.HALF) XP=1-XP
+ ELSEIF (RN.LT.B1+B2) THEN
+ XPMAX=0.83
+ XP=XPMAX*HWR()
+ ZPMIN=MAX(XP,1-XP)
+ ZPMAX=1-2./3.*XP*(1+REAL( CMPLX(10-45*XP+18*XP**2,3*SQRT(
+ $ 3*(9+66*XP-93*XP**2+12*XP**3-8*XP**4+24*XP**5-8*XP**6)))
+ $ **(1./3.) * CMPLX(0.5,0.8660254) ))
+ ZP=1-((1-ZPMIN)/(1-ZPMAX))**HWR()*(1-ZPMAX)
+ FAC=1/B2*XPMAX*LOG((1-ZPMIN)/(1-ZPMAX))*
+ $ (( XP+ZP-2*XP*ZP)**2+2*(1-XP)*(1-ZP)*XP*ZP
+ $ +(1-XP-ZP+2*XP*ZP)**2+2*(1-XP)*(1-ZP)*XP*ZP)
+ ELSE
+ XPMAX=0.83
+ XP=XPMAX*HWR()
+ ZPMAX=MIN(XP,1-XP)
+ ZPMIN=2./3.*XP*(1+REAL( CMPLX(10-45*XP+18*XP**2,3*SQRT(
+ $ 3*(9+66*XP-93*XP**2+12*XP**3-8*XP**4+24*XP**5-8*XP**6)))
+ $ **(1./3.) * CMPLX(0.5,0.8660254) ))
+ ZP=(ZPMAX-ZPMIN)*HWR()+ZPMIN
+ FAC=1/(1-B1-B2)*XPMAX*(ZPMAX-ZPMIN)/(1-ZP)*
+ $ (( XP+ZP-2*XP*ZP)**2+2*(1-XP)*(1-ZP)*XP*ZP
+ $ +(1-XP-ZP+2*XP*ZP)**2+2*(1-XP)*(1-ZP)*XP*ZP)
+ ENDIF
+ ZPMAX=1-2./3.*XP*(1+REAL( CMPLX(10-45*XP+18*XP**2,3*SQRT(
+ $ 3*(9+66*XP-93*XP**2+12*XP**3-8*XP**4+24*XP**5-8*XP**6)))
+ $ **(1./3.) * CMPLX(0.5,0.8660254) ))
+ IF (ZP.GT.ZPMAX.OR.ZP.LT.ONE-ZPMAX.OR.BM*HWR().GT.FAC)
+ $ GOTO 110
+ ENDIF
+C---CALCULATE THE ADDITIONAL FACTORS IN THE WEIGHT
+ IF (BGF) THEN
+ IDNEW=13
+ CFAC=1./2
+ FAC=BGFINT/(1-COMWGT)
+ ELSE
+ IDNEW=ID
+ CFAC=4./3
+ FAC=COMINT/COMWGT
+ ENDIF
+ SCALE=Q*SQRT((1-XP)*(1-ZP)*ZP/XP+1)
+ ITEMP=ISTAT
+ ISTAT=7
+ CALL HWSFUN(XBJ,Q,IDHW(IHAD),NSTRU,PDFOLD,2)
+ ISTAT=ITEMP
+ IF (PDFOLD(ID).LE.ZERO) CALL HWWARN('HWBDIS',100,*999)
+ IF (XP.GT.XBJ) THEN
+ CALL HWSFUN(XBJ/XP,SCALE,IDHW(IHAD),NSTRU,PDFNEW,2)
+ FAC=CFAC/(2*PIFAC) * HWUALF(1,SCALE) * FAC *
+ $ PDFNEW(IDNEW)/PDFOLD(ID)
+ ELSE
+ FAC=0
+ ENDIF
+C---FOR PHOTON BEAMS, INCLUDE DIRECT PHOTON COUPLING
+ IF (IDHW(IHAD).EQ.59) THEN
+ ZPMIN=2./3.*XBJ*(1+REAL( CMPLX(10-45*XBJ+18*XBJ**2,3*SQRT(
+ $ 3*(9+66*XBJ-93*XBJ**2+12*XBJ**3-8*XBJ**4+24*XBJ**5
+ $ -8*XBJ**6)))**(1./3.) * CMPLX(0.5,0.8660254) ))
+ ZPMAX=1-ZPMIN
+ DIR1=(XBJ**2+(1-XBJ)**2)*(LOG(ZPMAX/ZPMIN)-(ZPMAX-ZPMIN))
+ DIR2=4*XBJ*(1-XBJ)*(ZPMAX-ZPMIN)
+ DIR=QFCH(MOD(ID-1,6)+1)**2*ALPHEM/(2*PIFAC*PDFOLD(ID))*XBJ
+ $ *(DIR1+DIR2)
+ ELSE
+ DIR=0
+ ENDIF
+C---DECIDE WHETHER TO MAKE AN EVENT HERE
+ IF (HWR().GT.FAC+DIR) RETURN
+C---FOR DIRECT COUPLING, CHOOSE ZP VALUE
+ IF ((FAC+DIR)*HWR().GT.FAC) THEN
+ IF ((DIR1+DIR2)*HWR().LT.DIR1) THEN
+ NTRY=0
+ 120 NTRY=NTRY+2
+ ZP=1-(ZPMAX/ZPMIN)**HWR()*ZPMIN
+ IF ((ZPMIN**2+(1-ZPMIN)**2)*HWR().GT.ZP**2+(1-ZP)**2)
+ $ GOTO 120
+ ELSE
+ ZP=SQRT((ZPMAX-ZPMIN)*HWR()+ZPMIN**2)
+ ENDIF
+ XP=XBJ
+ BGF=.TRUE.
+ P3(5)=P2(5)
+ P1(5)=0
+ ENDIF
+ X1=1- ZP /XP
+ X2=1-(1-ZP)/XP
+ XTSQ=4*(1-XP)*(1-ZP)*ZP/XP
+ XT=SQRT(XTSQ)
+ SIN1=XT/SQRT(X1**2+XTSQ)
+ SIN2=XT/SQRT(X2**2+XTSQ)
+C---CHOOSE THE AZIMUTH BETWEEN THE TWO PLANES
+ IF (BGF) THEN
+ W1=XP**2*(X1**2+1.5*XTSQ)
+ ELSE
+ W1=1
+ ENDIF
+ W2=XP**2*(X2**2+1.5*XTSQ)
+ IF (HWR()*(W1+W2).GT.W2) THEN
+ IF (BGF) THEN
+C-----WEIGHTED BY (1+SIN1*COS(PHI))**2
+ 200 PHI=(2*HWR()-1)*PIFAC
+ IF (HWR()*(1+SIN1)**2.GT.(1+SIN1*COS(PHI))**2) GOTO 200
+ ELSE
+C-----UNIFORMLY
+ PHI=(2*HWR()-1)*PIFAC
+ ENDIF
+ ELSE
+C-----WEIGHTED BY (1-SIN2*COS(PHI))**2
+ 210 PHI=(2*HWR()-1)*PIFAC
+ IF (HWR()*(1+SIN2)**2.GT.(1-SIN2*COS(PHI))**2) GOTO 210
+ ENDIF
+C---RECONSTRUCT MOMENTA AND BOOST BACK TO LAB
+ P1(1)=0
+ P1(2)=0
+ P1(3)=HALF*Q/XP
+ P1(4)=SQRT(P1(3)**2+P1(5)**2)
+ PTSQ=((ZP*Q*(P1(4)+P1(3)-Q)-P2(5)**2)*(P1(4)-P1(3)+(1-ZP)*Q)
+ $ -P3(5)**2*ZP*Q)/(P1(4)-P1(3)+Q)
+C---CHECK INFRARED CUTOFF FOR THIS PARTON TYPE
+ IF (PTSQ.LT.MAX(HWBVMC(ID),HWBVMC(IDHW(IOUT)))**2) RETURN
+ P2(1)=SQRT(PTSQ)*COS(PHI)
+ P2(2)=SQRT(PTSQ)*SIN(PHI)
+ P2(3)=-0.5*(ZP*Q-(PTSQ+P2(5)**2)/(ZP*Q))
+ P2(4)= 0.5*(ZP*Q+(PTSQ+P2(5)**2)/(ZP*Q))
+ P3(1)=P1(1)-P2(1)
+ P3(2)=P1(2)-P2(2)
+ P3(3)=P1(3)-P2(3)-Q
+ P3(4)=P1(4)-P2(4)
+ CALL HWUROB(R,P1,P1)
+ CALL HWUROB(R,P2,P2)
+ CALL HWUROB(R,P3,P3)
+ CALL HWULOB(PCMF,P1,P1)
+ CALL HWULOB(PCMF,P2,P2)
+ CALL HWULOB(PCMF,P3,P3)
+C---SPECIAL CASE FOR DIRECT PHOTON - COPY THE EXACT BEAM MOMENTUM
+C---SHARE THE MISMATCH EQUALLY BETWEEN THE OUTGOING PARTONS
+C---AND PUT THEM BACK ON SHELL
+ IF (XP.EQ.XBJ) THEN
+ CALL HWVDIF(4,PHEP(1,IHAD),P1,PM)
+ CALL HWVSCA(4,HALF,PM,PM)
+ CALL HWVSUM(4,PM,P2,P2)
+ CALL HWVSUM(4,PM,P3,P3)
+ CALL HWUMAS(P2)
+ CALL HWUMAS(P3)
+ CALL HWVEQU(5,PHEP(1,IHAD),P1)
+ CALL HWVSUM(4,P2,P3,PCMF)
+ CALL HWUMAS(PCMF)
+ POLD=HWULDO(P2,PCMF)**2/PCMF(5)**2-SIGN(P2(5)**2,P2(5))
+ PNEW=PCMF(5)**2/4-RMASS(ID)**2
+ IF (PCMF(5).LE.ZERO.OR.POLD.LE.ZERO.OR.PNEW.LE.ZERO) RETURN
+ CALL HWVSCA(4,SQRT(PNEW/POLD),P2,P2)
+ CALL HWVSCA(4,HALF-HWULDO(P2,PCMF)/PCMF(5)**2,PCMF,PM)
+ CALL HWVSUM(4,PM,P2,P2)
+ CALL HWUMAS(P2)
+ CALL HWVDIF(4,PCMF,P2,P3)
+ CALL HWUMAS(P3)
+ ENDIF
+ NHEP=NHEP+1
+ CALL HWVEQU(5,P1,PHEP(1,IIN))
+ IF (BGF.AND.ID.GT.6.OR..NOT.BGF.AND.ID.LT.7) THEN
+ CALL HWVEQU(5,P2,PHEP(1,IOUT))
+ CALL HWVEQU(5,P3,PHEP(1,NHEP))
+ ELSE
+ CALL HWVEQU(5,P3,PHEP(1,IOUT))
+ CALL HWVEQU(5,P2,PHEP(1,NHEP))
+ ENDIF
+ CALL HWVSUM(4,PHEP(1,ILEP),PHEP(1,IIN),PHEP(1,ICMF))
+ CALL HWUMAS(PHEP(1,ICMF))
+C Decide which quark radiated and assign production vertices
+ IF (BGF) THEN
+C Boson-Gluon fusion case
+ IF (1-ZP.LT.HWR()) THEN
+C Gluon splitting to quark
+ CALL HWVZRO(4,VHEP(1,NHEP-1))
+ CALL HWVDIF(4,PHEP(1,NHEP-4),PHEP(1,NHEP),PVRT)
+ CALL HWUDKL(ID,PVRT,VHEP(1,NHEP))
+ CALL HWVEQU(4,VHEP(1,NHEP),VHEP(1,NHEP-4))
+ ELSE
+C Gluon splitting to antiquark
+ CALL HWVZRO(4,VHEP(1,NHEP))
+ CALL HWVDIF(4,PHEP(1,NHEP-4),PHEP(1,NHEP-1),PVRT)
+ CALL HWUDKL(ID,PVRT,VHEP(1,NHEP-1))
+ CALL HWVEQU(4,VHEP(1,NHEP-1),VHEP(1,NHEP-4))
+ ENDIF
+ ELSE
+C QCD Compton case
+ IF (1.LT.HWR()*(1+(1-XP-ZP)**2+6*XP*(1-XP)*ZP*(1-ZP)))THEN
+C Incoming quark radiated the gluon
+ CALL HWVZRO(4,VHEP(1,NHEP-1))
+ CALL HWVDIF(4,PHEP(1,NHEP-4),PHEP(1,NHEP),PVRT)
+ CALL HWUDKL(ID,PVRT,VHEP(1,NHEP))
+ CALL HWVEQU(4,VHEP(1,NHEP),VHEP(1,NHEP-4))
+ ELSE
+C Outgoing quark radiated the gluon
+ CALL HWVZRO(4,VHEP(1,NHEP-4))
+ CALL HWVSUM(4,PHEP(1,NHEP-1),PHEP(1,NHEP),PVRT)
+ CALL HWUDKL(ID,PVRT,VHEP(1,NHEP))
+ CALL HWVEQU(4,VHEP(1,NHEP),VHEP(1,NHEP-1))
+ ENDIF
+ ENDIF
+C---STATUS, ID AND POINTERS
+ ISTHEP(NHEP)=114
+ IF (BGF) THEN
+ IF (XP.EQ.XBJ) THEN
+ IDHW(IIN)=59
+ IDHEP(IIN)=IDPDG(59)
+ ELSE
+ IDHW(IIN)=13
+ IDHEP(IIN)=IDPDG(13)
+ ENDIF
+ IF (ID.LT.7) THEN
+ IDHW(NHEP)=IDHW(IOUT)
+ IDHEP(NHEP)=IDHEP(IOUT)
+ IDHW(IOUT)=MOD(ID,6)+6
+ IDHEP(IOUT)=IDPDG(IDHW(IOUT))
+ ELSE
+ IDHW(NHEP)=MOD(ID,6)
+ IDHEP(NHEP)=IDPDG(IDHW(NHEP))
+ ENDIF
+ ELSEIF (ID.LT.7) THEN
+ IDHW(NHEP)=13
+ IDHEP(NHEP)=IDPDG(13)
+ ELSE
+ IDHW(NHEP)=IDHW(IOUT)
+ IDHEP(NHEP)=IDHEP(IOUT)
+ IDHW(IOUT)=13
+ IDHEP(IOUT)=IDPDG(13)
+ ENDIF
+ JDAHEP(2,ICMF)=NHEP
+ JMOHEP(1,NHEP)=ICMF
+C---COLOUR CONNECTIONS
+ IF (XP.EQ.XBJ) THEN
+ JMOHEP(2,IIN)=IIN
+ JDAHEP(2,IIN)=IIN
+ JMOHEP(2,IOUT)=NHEP
+ JDAHEP(2,IOUT)=NHEP
+ JMOHEP(2,NHEP)=IOUT
+ JDAHEP(2,NHEP)=IOUT
+ ELSE
+ JDAHEP(2,IIN)=NHEP
+ JDAHEP(2,NHEP)=IOUT
+ JMOHEP(2,IOUT)=NHEP
+ JMOHEP(2,NHEP)=IIN
+ ENDIF
+C---FACTORISATION SCALE
+ EMSCA=SCALE
+ EMIT=NEVHEP+NWGTS
+ ELSEIF (IOPT.EQ.2) THEN
+C---MAKE TWO-JET EVENTS LOOK LIKE ONE-JET EVENTS
+ IF (EMIT.NE.NEVHEP+NWGTS .OR. XP.EQ.XBJ) RETURN
+ IF (.NOT.BGF) THEN
+ CALL HWVEQU(5,Q1,PHEP(1,IIN))
+ CALL HWVEQU(5,Q2,PHEP(1,IOUT))
+ JMOHEP(2,IIN)=IOUT
+ JDAHEP(2,IIN)=IOUT
+ JMOHEP(2,IOUT)=IIN
+ JDAHEP(2,IOUT)=IIN
+ JDAHEP(2,ICMF)=IOUT
+ IHEP=JDAHEP(1,IOUT)
+ JHEP=JDAHEP(1,IOUT+1)
+ CALL HWVSUM(4,PHEP(1,IHEP),PHEP(1,JHEP),PHEP(1,IHEP))
+ CALL HWUMAS(PHEP(1,IHEP))
+ JDAHEP(2,IHEP)=JDAHEP(2,JHEP)
+ IEDT(1)=IOUT+1
+ IEDT(2)=JHEP
+ IEDT(3)=JHEP+1
+ NDEL=3
+ IF (ISTHEP(JHEP+1).NE.100) NDEL=2
+ IHEP=JDAHEP(1,IOUT)
+ JMOHEP(1,IHEP)=IOUT
+ IF (ISTHEP(IHEP+1).EQ.100) THEN
+ JMOHEP(1,IHEP+1)=IOUT
+ JMOHEP(2,IHEP+1)=IIN
+ ENDIF
+ DO 300 JHEP=JDAHEP(1,IHEP),JDAHEP(2,IHEP)
+ JMOHEP(1,JHEP)=IHEP
+ 300 CONTINUE
+ IF (IDHW(IOUT).EQ.13) IDHW(IOUT)=IDHW(IOUT+1)
+ IDHEP(IOUT)=IDPDG(IDHW(IOUT))
+ IDHW(IHEP)=IDHW(IOUT)
+ CALL HWUEDT(NDEL,IEDT)
+ ELSEIF (ID.LT.7) THEN
+ CALL HWVEQU(5,Q1,PHEP(1,IIN))
+ CALL HWVEQU(5,Q2,PHEP(1,IOUT+1))
+ JMOHEP(2,IIN)=IOUT+1
+ JDAHEP(2,IIN)=IOUT+1
+ JMOHEP(2,IOUT+1)=IIN
+ JDAHEP(2,IOUT+1)=IIN
+ JDAHEP(2,ICMF)=IOUT+1
+ IHEP=JDAHEP(1,IIN)
+ JHEP=JDAHEP(1,IOUT)
+ CALL HWVDIF(4,PHEP(1,IHEP),PHEP(1,JHEP),PHEP(1,IHEP))
+ CALL HWUMAS(PHEP(1,IHEP))
+ CALL HWVDIF(4,PHEP(1,ICMF),PHEP(1,JHEP),PHEP(1,ICMF))
+ CALL HWUMAS(PHEP(1,ICMF))
+ CALL HWUEMV(JDAHEP(2,JHEP)-JDAHEP(1,JHEP)+1,
+ $ JDAHEP(1,JHEP),JDAHEP(2,IHEP))
+ JHEP=JDAHEP(1,IOUT)
+ JDAHEP(2,IHEP)=JDAHEP(2,JHEP)
+ IEDT(1)=IOUT
+ IEDT(2)=JHEP
+ IEDT(3)=JHEP+1
+ NDEL=3
+ IF (ISTHEP(JHEP+1).NE.100) NDEL=2
+ CALL HWUEDT(NDEL,IEDT)
+ IHEP=JDAHEP(1,IIN)
+ DO 400 JHEP=JDAHEP(1,IHEP),JDAHEP(2,IHEP)
+ JMOHEP(1,JHEP)=IHEP
+ 400 CONTINUE
+ IDHW(IIN)=ID
+ IDHEP(IIN)=IDPDG(ID)
+ IDHW(IHEP)=ID
+ ELSE
+ CALL HWVEQU(5,Q1,PHEP(1,IIN))
+ CALL HWVEQU(5,Q2,PHEP(1,IOUT))
+ JMOHEP(2,IIN)=IOUT
+ JDAHEP(2,IIN)=IOUT
+ JMOHEP(2,IOUT)=IIN
+ JDAHEP(2,IOUT)=IIN
+ JDAHEP(2,ICMF)=IOUT
+ IHEP=JDAHEP(1,IIN)
+ JHEP=JDAHEP(1,IOUT+1)
+ CALL HWVDIF(4,PHEP(1,IHEP),PHEP(1,JHEP),PHEP(1,IHEP))
+ CALL HWUMAS(PHEP(1,IHEP))
+ CALL HWVDIF(4,PHEP(1,ICMF),PHEP(1,JHEP),PHEP(1,ICMF))
+ CALL HWUMAS(PHEP(1,ICMF))
+ CALL HWUEMV(JDAHEP(2,JHEP)-JDAHEP(1,JHEP)+1,
+ $ JDAHEP(1,JHEP),JDAHEP(1,IHEP)-1)
+ JHEP=JDAHEP(1,IOUT+1)
+ JDAHEP(1,IHEP)=JDAHEP(1,JHEP)
+ IEDT(1)=IOUT+1
+ IEDT(2)=JHEP
+ IEDT(3)=JHEP+1
+ NDEL=3
+ IF (ISTHEP(JHEP+1).NE.100.OR.JHEP.EQ.NHEP) NDEL=2
+ CALL HWUEDT(NDEL,IEDT)
+ IHEP=JDAHEP(1,IIN)
+ DO 500 JHEP=JDAHEP(1,IHEP),JDAHEP(2,IHEP)
+ JMOHEP(1,JHEP)=IHEP
+ 500 CONTINUE
+ IDHW(IIN)=ID
+ IDHEP(IIN)=IDPDG(ID)
+ IDHW(IHEP)=ID
+ ENDIF
+ CALL HWVZRO(4,VHEP(1,IIN))
+ CALL HWVZRO(4,VHEP(1,JDAHEP(1,IIN)))
+ IF (ISTHEP(JDAHEP(1,IIN)+1).EQ.100)
+ $ CALL HWVZRO(4,VHEP(1,JDAHEP(1,IIN)+1))
+ CALL HWVZRO(4,VHEP(1,IOUT))
+ CALL HWVZRO(4,VHEP(1,JDAHEP(1,IOUT)))
+ IF (ISTHEP(JDAHEP(1,IOUT)+1).EQ.100)
+ $ CALL HWVZRO(4,VHEP(1,JDAHEP(1,IOUT)+1))
+ EMIT=0
+ ELSE
+ CALL HWWARN('HWBDIS',500,*999)
+ ENDIF
+ 999 END
+CDECK ID>, HWBDYP.
+*CMZ :- -26/10/99 17.46.56 by Mike Seymour
+*-- Author : Gennaro Corcella
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBDYP(IOPT)
+C MATRIX ELEMENT CORRECTIONS TO DRELL-YAN PROCESSES
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWBVMC,HWR,HWUALF,HWUSQR,PMODK,AZ,CZ,
+ & T,U,S,EM,TMIN,TMAX,PMOD2,GLUFAC,SMIN,SMAX,SZ,TEST,
+ & JAC,M(3),W1,W,PMOD3,SCAPR,CPHI,SPHI,SCALE,XI1,XI2,
+ & PDFOLD1(13),PDFOLD2(13),PDFNEW1(13),PDFNEW2(13),ETA1,ETA2,Y,
+ & COMWGT1,COMWGT2,WW,COS3,MODP,RN,BETA1,SIN3,R3(3,3),CTH,STH,M1,
+ & M2,M3,GAMMA1,R5(3,3),CW,SW,R4(3,3),SCALE1,X1,X2,X3,MM,
+ & PHAD1(5),PHAD2(5),P1(5),P2(5),P3(5),P4(5),PF(5),PV(5),PK(5),
+ & PR(5),PNE(5),PE(5),PP1(5),PP2(5),PZ(5),PS(5),PD(5),P2N(5),
+ & PBOS(5),PLAB(5),PTOT(5),P3N(5),SVNTN
+ LOGICAL GLUIN,GP
+ INTEGER EMIT,NOEMIT,IHEP,JHEP,KHEP,ICMF,IOPT,CHEP,
+ & ID2,ID1,K,ID4,ID5,IDBOS,IHAD1,IHAD2,NTMP
+ EXTERNAL HWBVMC,HWR,HWUALF,HWUSQR
+ SAVE ICMF,ID4,ID5
+ DATA EMIT,NTMP/2*0/
+ IF (IOPT.EQ.1) THEN
+ EMIT=0
+ NTMP=0
+C-----CHOOSE WEIGHTS
+ COMWGT1=0.1
+ COMWGT2=0.55
+C---FIND AN UNTREATED CMF
+ ICMF=0
+ DO 10 IHEP=1,NHEP
+ 10 IF (ICMF.EQ.0 .AND. ISTHEP(IHEP).EQ.110.AND.
+ & JDAHEP(2,IHEP).EQ.JDAHEP(1,IHEP)+1) ICMF=IHEP
+ IF (ICMF.EQ.0) RETURN
+ EM=PHEP(5,ICMF)
+C-----SET THE VECTOR BOSON RAPIDITY
+ Y=HALF*LOG((PHEP(4,ICMF)+PHEP(3,ICMF))/
+ & (PHEP(4,ICMF)-PHEP(3,ICMF)))
+C------SET PARTICLE IDENTIES
+c------ID1=QUARK, ID2=ANTIQUARK, IDBOS=VECTOR BOSON, ID4-5 BOSON DECAY
+ IDBOS=IDHW(ICMF)
+ ID1=IDHW(JMOHEP(1,ICMF))
+ ID2=IDHW(JMOHEP(2,ICMF))
+ ID4=IDHW(JDAHEP(1,ICMF))
+ ID5=IDHW(JDAHEP(2,ICMF))
+ M1=RMASS(ID1)
+ M2=RMASS(ID2)
+ M3=RMASS(13)
+C---STORE OLD MOMENTA
+C------VECTOR BOSON MOMENTUM
+ CALL HWVEQU(5,PHEP(1,ICMF),PBOS)
+C----QUARK MOMENTUM
+ CALL HWVEQU(5,PHEP(1,JMOHEP(1,ICMF)),P1)
+C------ANTIQUARK MOMENTUM
+ CALL HWVEQU(5,PHEP(1,JMOHEP(2,ICMF)),P2)
+C-------VECTOR DECAY (LEPTON) PRODUCT MOMENTA
+ CALL HWVEQU(5,PHEP(1,JDAHEP(1,ICMF)),P3)
+ CALL HWVEQU(5,PHEP(1,JDAHEP(2,ICMF)),P4)
+C------LEPTON MOMENTA IN THE BOSON REST FRAME
+ CALL HWULOF(PHEP(1,ICMF),P2,P2N)
+ CALL HWULOF(PHEP(1,ICMF),P3,P3N)
+C------AZ=AZIMUTHAL ANGLE OF P3N
+ AZ=ATAN2(P3N(2),P3N(1))
+ CZ=COS(AZ)
+ SZ=SIN(AZ)
+C------PHI=ANGLE BETWEEN P2N AND P3N
+ SCAPR=P2N(1)*P3N(1)+P2N(2)*P3N(2)+P2N(3)*P3N(3)
+ PMOD2=SQRT(P2N(1)**2+P2N(2)**2+P2N(3)**2)
+ PMOD3=SQRT(P3N(1)**2+P3N(2)**2+P3N(3)**2)
+ CPHI=SCAPR/(PMOD3*PMOD2)
+ SPHI=SQRT(1-CPHI**2)
+C------HADRON MOMENTA
+ IHAD1=1
+ IHAD2=2
+ IF (JDAHEP(1,IHAD1).NE.0) IHAD1=JDAHEP(1,IHAD1)
+ IF (JDAHEP(1,IHAD2).NE.0) IHAD2=JDAHEP(1,IHAD2)
+ CALL HWVEQU(5,PHEP(1,IHAD1),PHAD1)
+ CALL HWVEQU(5,PHEP(1,IHAD2),PHAD2)
+ CALL HWVSUM(4,PHAD1,PHAD2,PTOT)
+ CALL HWUMAS(PTOT)
+C------ Q - QBAR ENERGY FRACTIONS (BORN PROCESS)
+ ETA1=P1(4)/PHAD1(4)
+ ETA2=P2(4)/PHAD2(4)
+C------ PDFs FOR THE BORN PROCESS
+ CALL HWSFUN(ETA1,EM,IDHW(IHAD1),NSTRU,PDFOLD1,1)
+ CALL HWSFUN(ETA2,EM,IDHW(IHAD2),NSTRU,PDFOLD2,2)
+C-------CONSIDER Q(QBAR) IN THE INITIAL STATE
+ RN=HWR()
+ IF (RN.LT.COMWGT1) THEN
+C-------NO GLUON IN THE INITIAL STATE
+ GLUIN=.FALSE.
+C---CHOOSE S ACCORDING TO 1/S**2
+ SVNTN=17
+ SMIN=HALF*EM**2*(7-SQRT(SVNTN))
+ SMAX=PTOT(5)**2
+ IF (SMAX.LE.SMIN) RETURN
+ S=SMIN*SMAX/(SMIN+HWR()*(SMAX-SMIN))
+ JAC=S**2*(1/SMIN-1/SMAX)
+C---CHOOSE T ACCORDING TO (S-EM**2)/(T*U)=1/T+1/U
+ TMAX=-HALF*EM**2*(3-HWUSQR(1+8*EM**2/S))
+ TMIN=EM**2-S-TMAX
+ IF (TMAX.LE.TMIN) RETURN
+ T=TMAX*(TMIN/TMAX)**HWR()
+ IF (HWR().GT.HALF) T=EM**2-S-T
+ U=EM**2-S-T
+ JAC=JAC*2*T*U/(S-EM**2)*LOG(TMIN/TMAX)
+ SCALE=SQRT(U*T/S)
+ SCALE1=SQRT(U*T/S+EM**2)
+ GLUFAC=0
+ IF (SCALE1.GT.HWBVMC(13)) GLUFAC=HWUALF(1,SCALE1)/(2*PIFAC)
+C----Q-QBAR ENERGY FRACTIONS FOR Q QBAR-> VG
+ XI1=(HALF/PHAD1(4))*EXP(Y)*SQRT(S*(S+T)/(S+U))
+ XI2=S/(4*XI1*PHAD1(4)*PHAD2(4))
+ IF (XI1.GE.1.OR.XI2.GE.1) RETURN
+C-----PDFs WITH AN EMITTED GLUON
+ CALL HWSFUN(XI1,SCALE,IDHW(IHAD1),NSTRU,PDFNEW1,1)
+ CALL HWSFUN(XI2,SCALE,IDHW(IHAD2),NSTRU,PDFNEW2,2)
+C------CALCULATE WEIGHT
+ W=JAC*((EM**2-T)**2+(EM**2-U)**2)/(S**2*T*U)
+ W1=(GLUFAC/COMWGT1)*W*PDFNEW1(ID1)*PDFNEW2(ID2)/(PDFOLD1(ID1)*
+ & PDFOLD2(ID2))*(CFFAC*ETA1*ETA2/(XI1*XI2))
+C-------CHOOSE WHICH PARTON WILL EMIT
+ EMIT=1
+ IF (HWR().LT.(EM**2-U)**2/((EM**2-U)**2+(EM**2-T)**2))
+ & EMIT=2
+ NOEMIT=3-EMIT
+ ELSE
+C--------GLUON IN THE INITIAL STATE
+ GLUIN=.TRUE.
+C---CHOOSE S ACCORDING TO 1/S**2
+ SMIN=EM**2
+ SMAX=PTOT(5)**2
+ IF (SMAX.LE.SMIN) RETURN
+ S=SMIN*SMAX/(SMIN+HWR()*(SMAX-SMIN))
+ JAC=S**2*(1/SMIN-1/SMAX)
+C---CHOOSE T ACCORDING TO 1/T
+ TMAX=-HALF*EM**2*(3-HWUSQR(1+8*EM**2/S))
+ TMIN=EM**2-S
+ IF (TMAX.LE.TMIN) RETURN
+ T=TMAX*(TMIN/TMAX)**HWR()
+ JAC=JAC*T*LOG(TMAX/TMIN)
+ U=EM**2-S-T
+ SCALE=SQRT(U*T/S)
+ SCALE1=SQRT(U*T/S+EM**2)
+ GLUFAC=0
+ IF (SCALE1.GT.HWBVMC(13)) GLUFAC=HWUALF(1,SCALE1)/(2*PIFAC)
+C--------INITIAL STATE GLUON COMING FROM HADRON 1
+ IF (RN.LE.COMWGT2) THEN
+ GP=.TRUE.
+C--------ENERGY FRACTIONS and PDFs
+ XI1=(HALF/PHAD1(4))*EXP(Y)*SQRT(S*(S+U)/(S+T))
+ XI2=S/(4*XI1*PHAD1(4)*PHAD2(4))
+ IF (XI1.GE.1.OR.XI2.GE.1) RETURN
+ CALL HWSFUN(XI1,SCALE,IDHW(IHAD1),NSTRU,PDFNEW1,1)
+ CALL HWSFUN(XI2,SCALE,IDHW(IHAD2),NSTRU,PDFNEW2,2)
+ WW=PDFNEW1(13)*PDFNEW2(ID2)/((COMWGT2-COMWGT1)*
+ & PDFOLD1(ID1)*PDFOLD2(ID2))
+ ELSE
+C-------INITIAL STATE GLUON COMING FROM HADRON 2
+ GP=.FALSE.
+C-------ENERGY FRACTIONS AND PDFs
+ XI1=(HALF/PHAD1(4))*EXP(Y)*SQRT(S*(S+T)/(S+U))
+ XI2=S/(4*XI1*PHAD1(4)*PHAD2(4))
+ IF (XI1.GE.1.OR.XI2.GE.1) RETURN
+ CALL HWSFUN(XI1,SCALE,IDHW(IHAD1),NSTRU,PDFNEW1,1)
+ CALL HWSFUN(XI2,SCALE,IDHW(IHAD2),NSTRU,PDFNEW2,2)
+ WW=PDFNEW1(ID1)*PDFNEW2(13)/((1-COMWGT2)*
+ & PDFOLD1(ID1)*PDFOLD2(ID2))
+ ENDIF
+ W=-HALF*JAC*((EM**2-T)**2+(EM**2-S)**2)/(S**3*T)
+C-------CHOOSE WHICH PARTON WILL EMIT
+ EMIT=1
+ IF (HWR().LT.(EM**2-S)**2/((EM**2-S)**2+(EM**2-T)**2))
+ & EMIT=2
+ NOEMIT=3-EMIT
+C-------FINAL WEIGHT FOR ALL THE CONSIDERED OPTIONS
+ W1=GLUFAC*W*WW*ETA1*ETA2/(XI1*XI2)
+ ENDIF
+C--------ADD ONE MORE GLUON
+ IF (W1.GT.HWR()) THEN
+ NTMP=NEVHEP+NWGTS
+ ELSE
+ RETURN
+ ENDIF
+C---------INCLUDE MASSES
+ S=S+M1**2+M2**2+M3**2
+ IF (.NOT.GLUIN) THEN
+ TEST=((S+M1**2-M2**2)*(S+M3**2-EM**2)-2*S*(M1**2+M3**2-T))**2
+ $ -((S-M1**2-M2**2)**2-4*M1**2*M2**2)*
+ $ ((S-M3**2-EM**2)**2-4*M3**2*EM**2)
+ ELSEIF (GP) THEN
+ TEST=((S+M3**2-M2**2)*(S+M1**2-EM**2)-2*S*(M3**2+M1**2-T))**2
+ $ -((S-M3**2-M2**2)**2-4*M3**2*M2**2)*
+ $ ((S-M1**2-EM**2)**2-4*M1**2*EM**2)
+ ELSE
+ TEST=((S+M3**2-M1**2)*(S+M2**2-EM**2)-2*S*(M3**2+M2**2-T))**2
+ $ -((S-M3**2-M1**2)**2-4*M3**2*M1**2)*
+ $ ((S-M2**2-EM**2)**2-4*M2**2*EM**2)
+ ENDIF
+ IF (TEST.GE.0) THEN
+ EMIT=0
+ RETURN
+ ENDIF
+ M(1)=M1
+ M(2)=M2
+ M(3)=M3
+C----MOMENTA IN THE V-REST FRAME WITH NON EMITTER ALONG THE Z AXIS
+C----V=BOSON,K=GLUON,E=EMITTER,NE=NON-EMITTER
+ PV(1)=0
+ PV(2)=0
+ PV(3)=0
+ PV(4)=EM
+ PV(5)=EM
+ PNE(2)=0
+ PNE(1)=0
+ IF (.NOT.GLUIN) THEN
+ PK(4)=(S-M(3)**2-EM**2)/(2*EM)
+ PMODK=SQRT(PK(4)**2-M(3)**2)
+ IF (EMIT.EQ.1) THEN
+ MM=M(1)
+ X1=T
+ X2=U
+ X3=-1
+ ELSE
+ MM=M(2)
+ X1=U
+ X2=T
+ X3=+1
+ ENDIF
+ PNE(4)=(EM**2+MM**2-X1)/(2*EM)
+ PNE(3)=X3*SQRT(PNE(4)**2-MM**2)
+ COS3=HALF*(X2-MM**2-M(3)**2+2*PNE(4)*PK(4))/(PNE(3)*PMODK)
+ ELSE
+ PK(4)=(EM**2+M(3)**2-U)/(2*EM)
+ PMODK=SQRT(PK(4)**2-M(3)**2)
+ IF (EMIT.EQ.1) THEN
+ IF (GP) THEN
+ MM=M(1)
+ X3=+1
+ ELSE
+ MM=M(2)
+ X3=-1
+ ENDIF
+ PNE(4)=(S-MM**2-EM**2)/(2*EM)
+ PNE(3)=X3*SQRT(PNE(4)**2-MM**2)
+ COS3=HALF*(T-MM**2-M(3)**2+2*PNE(4)*PK(4))/(PNE(3)*PMODK)
+ ELSE
+ IF (GP) THEN
+ MM=M(2)
+ X3=-1
+ ELSE
+ MM=M(1)
+ X3=+1
+ ENDIF
+ PNE(4)=(EM**2+MM**2-T)/(2*EM)
+ PNE(3)=X3*SQRT(PNE(4)**2-MM**2)
+ COS3=HALF*(MM**2+M(3)**2-S+2*PNE(4)*PK(4))/(PNE(3)*PMODK)
+ ENDIF
+ ENDIF
+ CALL HWUMAS(PNE)
+ SIN3=SQRT(1-COS3**2)
+C---------DEFINE A RANDOM ROTATION AROUND THE Z-AXIS
+ CALL HWRAZM(PMODK*SIN3,PK(1),PK(2))
+ PK(3)=PMODK*COS3
+ CALL HWUMAS(PK)
+ DO K=1,4
+ IF (.NOT.GLUIN) THEN
+ PE(K)=PV(K)+PK(K)-PNE(K)
+ ELSE
+ IF (EMIT.EQ.1) THEN
+ PE(K)=PV(K)+PNE(K)-PK(K)
+ ELSE
+ PE(K)=PNE(K)+PK(K)-PV(K)
+ ENDIF
+ ENDIF
+ ENDDO
+ CALL HWUMAS(PE)
+c------LEPTON MOMENTA IN THE BOSON REST FRAME, WITH THE DIRECTION
+C------TAKEN FROM THE BORN PROCESS
+ PS(5)=P3(5)
+ PS(4)=(EM**2+P3(5)**2-P4(5)**2)/(2*EM)
+ PS(3)=-SQRT(PS(4)**2-P3(5)**2)*CPHI
+ PS(2)=SQRT(PS(4)**2-P3(5)**2)*SPHI*SZ
+ PS(1)=SQRT(PS(4)**2-P3(5)**2)*SPHI*CZ
+ PF(5)=P4(5)
+ PF(4)=(EM**2+P4(5)**2-P3(5)**2)/(2*EM)
+ PF(3)=-PS(3)
+ PF(2)=-PS(2)
+ PF(1)=-PS(1)
+C----FIND A STATIONARY VECTOR PLAB IN THE LAB FRAME
+ IF (.NOT.GLUIN) THEN
+ IF (EMIT.EQ.1) THEN
+ CALL HWVEQU(5,PE,PP1)
+ CALL HWVEQU(5,PNE,PP2)
+ ELSE
+ CALL HWVEQU(5,PNE,PP1)
+ CALL HWVEQU(5,PE,PP2)
+ ENDIF
+ ELSE
+ IF (GP) THEN
+ CALL HWVEQU(5,PK,PP1)
+ IF (EMIT.EQ.1) THEN
+ CALL HWVEQU(5,PE,PP2)
+ ELSE
+ CALL HWVEQU(5,PNE,PP2)
+ ENDIF
+ ELSE
+ CALL HWVEQU(5,PK,PP2)
+ IF (EMIT.EQ.1) THEN
+ CALL HWVEQU(5,PE,PP1)
+ ELSE
+ CALL HWVEQU(5,PNE,PP1)
+ ENDIF
+ ENDIF
+ ENDIF
+ CALL HWVSCA(4,1/XI1,PP1,PP1)
+ CALL HWVSCA(4,1/XI2,PP2,PP2)
+ CALL HWVSUM(4,PP1,PP2,PLAB)
+ CALL HWUMAS(PLAB)
+C------BOOST TO PLAB REST FRAME
+ CALL HWULOF(PLAB,PE,PE)
+ CALL HWULOF(PLAB,PNE,PNE)
+ CALL HWULOF(PLAB,PK,PK)
+ CALL HWULOF(PLAB,PS,PS)
+ CALL HWULOF(PLAB,PF,PF)
+ CALL HWULOF(PLAB,PV,PV)
+C----PUT THE INITIAL PARTON BELONGING TO HADRON 1 ON THE Z-AXIS
+ IF (.NOT.GLUIN) THEN
+ IF (EMIT.EQ.1) THEN
+ CALL HWVEQU(5,PE,PZ)
+ ELSE
+ CALL HWVEQU(5,PNE,PZ)
+ ENDIF
+ ELSE
+ IF (GP) THEN
+ CALL HWVEQU(5,PK,PZ)
+ ELSE
+ IF (EMIT.EQ.1) THEN
+ CALL HWVEQU(5,PE,PZ)
+ ELSE
+ CALL HWVEQU(5,PNE,PZ)
+ ENDIF
+ ENDIF
+ ENDIF
+ MODP=SQRT(PZ(1)**2+PZ(2)**2)
+ CTH=PZ(1)/MODP
+ STH=PZ(2)/MODP
+ CALL HWUROT(PZ,CTH,STH,R3)
+C-----ROTATE EVERYTHING BY R3
+ CALL HWUROF(R3,PE,PE)
+ CALL HWUROF(R3,PNE,PNE)
+ CALL HWUROF(R3,PV,PV)
+ CALL HWUROF(R3,PK,PK)
+ CALL HWUROF(R3,PS,PS)
+ CALL HWUROF(R3,PF,PF)
+C--REORDER ENTRIES:--IHEP=EMITTER,JHEP=NON-EMITTER,KHEP=EMITTED
+ IF (.NOT.GLUIN) THEN
+ IHEP=JMOHEP(EMIT,ICMF)
+ JHEP=JMOHEP(NOEMIT,ICMF)
+ ENDIF
+ CHEP=ICMF
+ IDHW(CHEP)=15
+ IDHEP(CHEP)=IDPDG(15)
+ ICMF=ICMF+1
+ IDHW(ICMF)=IDBOS
+ IDHEP(ICMF)=IDPDG(IDBOS)
+C-----NO GLUON IN THE INITIAL STATE: JUST ADD IT AFTER THE VECTOR BOSON
+ IF (.NOT.GLUIN) THEN
+ KHEP=ICMF+1
+ ISTHEP(KHEP)=114
+C---STATUS OF EMITTER/NON EMITTER
+ ISTHEP(IHEP)=110+EMIT
+ ISTHEP(JHEP)=110+NOEMIT
+ ELSE
+C-----GLUON COMING FROM THE 1ST HADRON
+ IF (GP) THEN
+ KHEP=CHEP-2
+ ISTHEP(KHEP)=111
+C----EMIT=1
+ IF (EMIT.EQ.1) THEN
+ IHEP=KHEP+1
+ ISTHEP(IHEP)=112
+ JHEP=ICMF+1
+ ISTHEP(JHEP)=114
+ IDHW(IHEP)=ID2
+ IF (ID1.LE.6) THEN
+ IDHW(JHEP)=ID1+6
+ ELSE
+ IDHW(JHEP)=ID1-6
+ ENDIF
+ ELSE
+C-------EMIT=2
+ JHEP=KHEP+1
+ ISTHEP(JHEP)=112
+ IDHW(JHEP)=ID2
+ IHEP=ICMF+1
+ ISTHEP(IHEP)=114
+ IF (ID1.LE.6) THEN
+ IDHW(IHEP)=ID1+6
+ ELSE
+ IDHW(IHEP)=ID1-6
+ ENDIF
+ ENDIF
+ ENDIF
+C------GLUON COMING FROM THE HADRON 2
+ IF (.NOT.GP) THEN
+ KHEP=CHEP-1
+ ISTHEP(KHEP)=112
+C-------EMIT=1
+ IF (EMIT.EQ.1) THEN
+ IHEP=KHEP-1
+ ISTHEP(IHEP)=111
+ IDHW(IHEP)=ID1
+ JHEP=ICMF+1
+ ISTHEP(JHEP)=114
+ IF (ID2.LE.6) THEN
+ IDHW(JHEP)=ID2+6
+ ELSE
+ IDHW(JHEP)=ID2-6
+ ENDIF
+ ELSE
+C-------EMIT=2
+ JHEP=KHEP-1
+ ISTHEP(JHEP)=111
+ IDHW(JHEP)=ID1
+ IHEP=ICMF+1
+ ISTHEP(IHEP)=114
+ IF (ID2.LE.6) THEN
+ IDHW(IHEP)=ID2+6
+ ELSE
+ IDHW(IHEP)=ID2-6
+ ENDIF
+ ENDIF
+ ENDIF
+ ENDIF
+ IDHEP(IHEP)=IDPDG(IDHW(IHEP))
+ IDHEP(JHEP)=IDPDG(IDHW(JHEP))
+ ISTHEP(ICMF)=113
+ ISTHEP(CHEP)=110
+ IDHW(KHEP)=13
+ IDHEP(KHEP)=IDPDG(13)
+C---------DEFINE MOMENTA IN THE LAB FRAME
+ CALL HWVEQU(5,PV,PHEP(1,ICMF))
+ CALL HWVEQU(5,PK,PHEP(1,KHEP))
+ CALL HWVEQU(5,PNE,PHEP(1,JHEP))
+ CALL HWVEQU(5,PE,PHEP(1,IHEP))
+ IF (.NOT.GLUIN) THEN
+ CALL HWVSUM(4,PHEP(1,IHEP),PHEP(1,JHEP),PHEP(1,CHEP))
+ ELSE
+ IF (EMIT.EQ.1) THEN
+ CALL HWVSUM(4,PHEP(1,IHEP),PHEP(1,KHEP),PHEP(1,CHEP))
+ ELSE
+ CALL HWVSUM(4,PHEP(1,KHEP),PHEP(1,JHEP),PHEP(1,CHEP))
+ ENDIF
+ ENDIF
+ CALL HWUMAS(PHEP(1,CHEP))
+ IF (.NOT.GLUIN) THEN
+ JMOHEP(1,JHEP)=CHEP
+ JMOHEP(1,IHEP)=CHEP
+ JDAHEP(1,JHEP)=CHEP
+ JDAHEP(1,IHEP)=CHEP
+ JMOHEP(1,KHEP)=CHEP
+ JDAHEP(1,KHEP)=0
+ JMOHEP(1,ICMF)=CHEP
+ JMOHEP(2,ICMF)=ICMF
+ JDAHEP(1,ICMF)=0
+ JDAHEP(2,ICMF)=ICMF
+ ENDIF
+ IF (GLUIN) THEN
+ JMOHEP(2,ICMF)=ICMF
+ JDAHEP(2,ICMF)=ICMF
+ JMOHEP(1,KHEP)=CHEP
+ JDAHEP(1,KHEP)=CHEP
+ JMOHEP(1,IHEP)=CHEP
+ JMOHEP(1,JHEP)=CHEP
+ IF (EMIT.EQ.1) THEN
+ JDAHEP(1,IHEP)=CHEP
+ JDAHEP(1,JHEP)=0
+ ELSE
+ JDAHEP(1,JHEP)=CHEP
+ JDAHEP(1,IHEP)=0
+ ENDIF
+ ENDIF
+C---COLOUR CONNECTIONS
+ IF (.NOT.GLUIN) THEN
+ IF (IDHW(IHEP).LT.IDHW(JHEP)) THEN
+ JMOHEP(2,KHEP)=IHEP
+ JDAHEP(2,KHEP)=JHEP
+ JMOHEP(2,IHEP)=JHEP
+ JDAHEP(2,IHEP)=KHEP
+ JDAHEP(2,JHEP)=IHEP
+ JMOHEP(2,JHEP)=KHEP
+ ELSE
+ JMOHEP(2,KHEP)=JHEP
+ JDAHEP(2,KHEP)=IHEP
+ JMOHEP(2,JHEP)=IHEP
+ JDAHEP(2,JHEP)=KHEP
+ JDAHEP(2,IHEP)=JHEP
+ JMOHEP(2,IHEP)=KHEP
+ ENDIF
+ ENDIF
+ IF (GLUIN) THEN
+ IF (EMIT.EQ.1) THEN
+ IF (IDHEP(IHEP).GT.0) THEN
+ JMOHEP(2,IHEP)=JHEP
+ JDAHEP(2,IHEP)=KHEP
+ JMOHEP(2,JHEP)=KHEP
+ JDAHEP(2,JHEP)=IHEP
+ JMOHEP(2,KHEP)=IHEP
+ JDAHEP(2,KHEP)=JHEP
+ ELSE
+ JMOHEP(2,IHEP)=KHEP
+ JDAHEP(2,IHEP)=JHEP
+ JMOHEP(2,JHEP)=IHEP
+ JDAHEP(2,JHEP)=KHEP
+ JMOHEP(2,KHEP)=JHEP
+ JDAHEP(2,KHEP)=IHEP
+ ENDIF
+ ELSE
+ IF (IDHEP(JHEP).GT.0) THEN
+ JMOHEP(2,JHEP)=IHEP
+ JDAHEP(2,JHEP)=KHEP
+ JMOHEP(2,IHEP)=KHEP
+ JDAHEP(2,IHEP)=JHEP
+ JMOHEP(2,KHEP)=JHEP
+ JDAHEP(2,KHEP)=IHEP
+ ELSE
+ JMOHEP(2,JHEP)=KHEP
+ JDAHEP(2,JHEP)=IHEP
+ JMOHEP(2,IHEP)=JHEP
+ JDAHEP(2,IHEP)=KHEP
+ JMOHEP(2,KHEP)=IHEP
+ JDAHEP(2,KHEP)=JHEP
+ ENDIF
+ ENDIF
+ ENDIF
+ EMSCA=SQRT(EM**2+PHEP(1,ICMF)**2+PHEP(2,ICMF)**2)
+C--------SET STATUS AND LEPTON MOMENTA AFTER THE PARTON SHOWER
+ ELSEIF (IOPT.EQ.2) THEN
+ IF (EMIT.EQ.0.OR.NEVHEP+NWGTS.NE.NTMP) RETURN
+ ISTHEP(JDAHEP(1,ICMF))=195
+ IDHW(NHEP+1)=ID4
+ IDHW(NHEP+2)=ID5
+ IDHEP(NHEP+1)=IDPDG(ID4)
+ IDHEP(NHEP+2)=IDPDG(ID5)
+ ISTHEP(NHEP+1)=113
+ ISTHEP(NHEP+2)=114
+ CW=PHEP(3,ICMF)/SQRT(PHEP(1,ICMF)**2+PHEP(2,ICMF)**2+
+ & PHEP(3,ICMF)**2)
+ SW=SQRT(1-CW**2)
+ CALL HWUROT(PHEP(1,ICMF),CW,SW,R4)
+ CALL HWUROF(R4,PHEP(1,ICMF),PR)
+ PR(4)=PHEP(4,ICMF)
+ CALL HWUMAS(PR)
+ CALL HWUROF(R4,PS,PS)
+ CALL HWUROF(R4,PF,PF)
+ CALL HWUMAS(PS)
+ CALL HWUMAS(PF)
+ CALL HWUROT(PHEP(1,JDAHEP(1,ICMF)),CW,SW,R5)
+ CALL HWUROF(R5,PHEP(1,JDAHEP(1,ICMF)),PD)
+ PD(4)=PHEP(4,JDAHEP(1,ICMF))
+ CALL HWUMAS(PD)
+ BETA1=(PR(4)*PR(3)-SQRT(PR(4)**2*PD(3)**2-PR(3)**2*PD(3)**2+
+ & PD(3)**4))/(PD(3)**2+PR(4)**2)
+ GAMMA1=1/SQRT(1-BETA1**2)
+ PHEP(4,NHEP+1)=GAMMA1*PS(4)-BETA1*GAMMA1*PS(3)
+ PHEP(3,NHEP+1)=-BETA1*GAMMA1*PS(4)+GAMMA1*PS(3)
+ PHEP(4,NHEP+2)=GAMMA1*PF(4)-BETA1*GAMMA1*PF(3)
+ PHEP(3,NHEP+2)=-BETA1*GAMMA1*PF(4)+GAMMA1*PF(3)
+ PHEP(1,NHEP+1)=PS(1)
+ PHEP(2,NHEP+1)=PS(2)
+ PHEP(1,NHEP+2)=PF(1)
+ PHEP(2,NHEP+2)=PF(2)
+ CALL HWUMAS(PHEP(1,NHEP+1))
+ CALL HWUMAS(PHEP(1,NHEP+2))
+ CALL HWUROB(R5,PHEP(1,NHEP+1),PHEP(1,NHEP+1))
+ CALL HWUROB(R5,PHEP(1,NHEP+2),PHEP(1,NHEP+2))
+ JDAHEP(1,JDAHEP(1,ICMF))=NHEP+1
+ JDAHEP(2,JDAHEP(1,ICMF))=NHEP+2
+ JMOHEP(1,NHEP+1)=JDAHEP(1,ICMF)
+ JMOHEP(1,NHEP+2)=JDAHEP(1,ICMF)
+ JMOHEP(2,NHEP+1)=NHEP+2
+ JDAHEP(2,NHEP+1)=NHEP+2
+ JMOHEP(2,NHEP+2)=NHEP+1
+ JDAHEP(2,NHEP+2)=NHEP+1
+ NHEP=NHEP+2
+ EMIT=0
+ ENDIF
+ END
+CDECK ID>, HWBFIN.
+*CMZ :- -26/04/91 10.18.56 by Bryan Webber
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBFIN(IHEP)
+C-----------------------------------------------------------------------
+C DELETES INTERNAL LINES FROM SHOWER, MAKES COLOUR CONNECTION INDEX
+C AND COPIES INTO /HEPEVT/ IN COLOUR ORDER.
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER IHEP,ID,IJET,KHEP,IPAR,JPAR,NXPAR,IP,JP
+ IF (IERROR.NE.0) RETURN
+C---SAVE VIRTUAL PARTON DATA
+ NHEP=NHEP+1
+ IF(NHEP.GT.NMXHEP) CALL HWWARN('HWBFIN',100,*999)
+ ID=IDPAR(2)
+ IDHW(NHEP)=ID
+ IDHEP(NHEP)=IDPDG(ID)
+ ISTHEP(NHEP)=ISTHEP(IHEP)+20
+ JMOHEP(1,NHEP)=IHEP
+ JMOHEP(2,NHEP)=JMOHEP(1,IHEP)
+ JDAHEP(1,IHEP)=NHEP
+ JDAHEP(1,NHEP)=0
+ JDAHEP(2,NHEP)=0
+ CALL HWVEQU(5,PPAR(1,2),PHEP(1,NHEP))
+ CALL HWVEQU(4,VPAR(1,2),VHEP(1,NHEP))
+C---FINISHED FOR SPECTATOR OR NON-PARTON JETS
+ IF (ISTHEP(NHEP).GT.136) RETURN
+ IF (ID.GT.13.AND.ID.LT.209 .AND. ID.NE.59) RETURN
+ IF (ID.GT.220.AND.ABS(IDPDG(ID)).LT.1000000) RETURN
+ IF (ID.GT.424.AND.ID.NE.449) RETURN
+ IF (.NOT.TMPAR(2).AND.ID.EQ.59) RETURN
+ IDHEP(NHEP)=94
+ IJET=NHEP
+ IF (NPAR.GT.2) THEN
+C---SAVE CONE DATA
+ NHEP=NHEP+1
+ IF(NHEP.GT.NMXHEP) CALL HWWARN('HWBFIN',101,*999)
+ IDHW(NHEP)=IDPAR(1)
+ IDHEP(NHEP)=0
+ ISTHEP(NHEP)=100
+ JMOHEP(1,NHEP)=IHEP
+ JMOHEP(2,NHEP)=JCOPAR(1,1)
+ JDAHEP(1,NHEP)=0
+ JDAHEP(2,NHEP)=0
+ CALL HWVEQU(5,PPAR,PHEP(1,NHEP))
+ CALL HWVEQU(4,VPAR(1,2),VHEP(1,NHEP))
+ ENDIF
+ KHEP=NHEP
+C---START WITH ANTICOLOUR DAUGHTER OF HARDEST PARTON
+ IPAR=2
+ JPAR=JCOPAR(4,IPAR)
+ NXPAR=NPAR/2
+ DO 20 IP=1,NXPAR
+ DO 10 JP=1,NXPAR
+ IF (JPAR.EQ.0) GOTO 15
+ IF (JCOPAR(2,JPAR).EQ.IPAR) THEN
+ IPAR=JPAR
+ JPAR=JCOPAR(4,IPAR)
+ ELSE
+ IPAR=JPAR
+ JPAR=JCOPAR(1,IPAR)
+ ENDIF
+ 10 CONTINUE
+C---COULDN'T FIND COLOUR PARTNER
+ CALL HWWARN('HWBFIN',1,*999)
+ 15 JPAR=JCOPAR(1,IPAR)
+ KHEP=KHEP+1
+ IF(KHEP.GT.NMXHEP) CALL HWWARN('HWBFIN',102,*999)
+ ID=IDPAR(IPAR)
+ IF (TMPAR(IPAR)) THEN
+ IF (ID.LT.14) THEN
+ ISTHEP(KHEP)=139
+ ELSEIF (ID.EQ.59) THEN
+ ISTHEP(KHEP)=139
+ ELSEIF (ID.LT.109) THEN
+ ISTHEP(KHEP)=130
+ ELSEIF (ID.LT.120) THEN
+ ISTHEP(KHEP)=139
+ ELSEIF (ABS(IDPDG(ID)).LT.1000000) THEN
+ ISTHEP(KHEP)=130
+ ELSEIF (ID.LT.425) THEN
+ ISTHEP(KHEP)=139
+ ELSEIF (ID.EQ.449) THEN
+ ISTHEP(KHEP)=139
+ ELSE
+ ISTHEP(KHEP)=130
+ ENDIF
+ ELSE
+ ISTHEP(KHEP)=ISTHEP(IHEP)+24
+ ENDIF
+ IDHW(KHEP)=ID
+ IDHEP(KHEP)=IDPDG(ID)
+ CALL HWVEQU(5,PPAR(1,IPAR),PHEP(1,KHEP))
+ CALL HWVEQU(4,VPAR(1,IPAR),VHEP(1,KHEP))
+ JMOHEP(1,KHEP)=IJET
+ JMOHEP(2,KHEP)=KHEP+1
+ JDAHEP(1,KHEP)=0
+ JDAHEP(2,KHEP)=KHEP-1
+ 20 CONTINUE
+ JMOHEP(2,KHEP)=0
+ JDAHEP(2,NHEP+1)=0
+ JDAHEP(1,IJET)=NHEP+1
+ JDAHEP(2,IJET)=KHEP
+ NHEP=KHEP
+ 999 END
+CDECK ID>, HWBGEN.
+*CMZ :- -14/10/99 18.04.56 by Mike Seymour
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBGEN
+C-----------------------------------------------------------------------
+C BRANCHING GENERATOR WITH INTERFERING GLUONS
+C HWBGEN EVOLVES QCD JETS ACCORDING TO THE METHOD OF
+C G.MARCHESINI & B.R.WEBBER, NUCL. PHYS. B238(1984)1
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWULDO,HWRGAU,EINHEP,ERTXI,RTXI,XF
+ INTEGER NTRY,LASHEP,IHEP,NRHEP,ID,IST,JHEP,KPAR,I,J,IRHEP(NMXJET),
+ & IRST(NMXJET)
+ LOGICAL HWRLOG
+ EXTERNAL HWULDO,HWRGAU
+ IF (IERROR.NE.0) RETURN
+ IF (IPRO.EQ.80) RETURN
+C---CHECK THAT EMSCA IS SET
+ IF (EMSCA.LE.ZERO) CALL HWWARN('HWBGEN',200,*999)
+ IF (HARDME) THEN
+C---FORCE A BRANCH INTO THE `DEAD ZONE' IN E+E-
+ IF (IPROC/10.EQ.10) CALL HWBDED(1)
+C---FORCE A BRANCH INTO THE `DEAD ZONE' IN DIS
+ IF (IPRO.EQ.90) CALL HWBDIS(1)
+C---FORCE A BRANCH INTO THE `DEAD ZONE' IN DRELL-YAN PROCESSES
+ IF (IPRO.EQ.13.OR.IPRO.EQ.14) CALL HWBDYP(1)
+C---FORCE A BRANCH INTO THE `DEAD ZONE' IN TOP DECAYS
+ CALL HWBTOP
+ ENDIF
+C---GENERATE INTRINSIC PT ONCE AND FOR ALL
+ DO 5 JNHAD=1,2
+ IF (PTRMS.NE.0.) THEN
+ PTINT(1,JNHAD)=HWRGAU(1,ZERO,PXRMS)
+ PTINT(2,JNHAD)=HWRGAU(2,ZERO,PXRMS)
+ PTINT(3,JNHAD)=PTINT(1,JNHAD)**2+PTINT(2,JNHAD)**2
+ ELSE
+ CALL HWVZRO(3,PTINT(1,JNHAD))
+ ENDIF
+ 5 CONTINUE
+ NTRY=0
+ LASHEP=NHEP
+ 10 NTRY=NTRY+1
+ IF (NTRY.GT.NETRY) CALL HWWARN('HWBGEN',ISLENT*100,*999)
+ NRHEP=0
+ NHEP=LASHEP
+ FROST=.FALSE.
+ DO 100 IHEP=1,LASHEP
+ IST=ISTHEP(IHEP)
+ IF (IST.GE.111.AND.IST.LE.115) THEN
+ NRHEP=NRHEP+1
+ IRHEP(NRHEP)=IHEP
+ IRST(NRHEP)=IST
+ ID=IDHW(IHEP)
+ IF (IST.NE.115) THEN
+C---FOUND A PARTON TO EVOLVE
+ NEVPAR=IHEP
+ NPAR=2
+ IDPAR(1)=17
+ IDPAR(2)=ID
+ TMPAR(1)=.TRUE.
+ PPAR(2,1)=0.
+ PPAR(4,1)=1.
+ DO 15 J=1,2
+ DO 15 I=1,2
+ JMOPAR(I,J)=0
+ 15 JCOPAR(I,J)=0
+C---SET UP EVOLUTION SCALE AND FRAME
+ JHEP=JMOHEP(2,IHEP)
+ IF (ID.EQ.13) THEN
+ IF (HWRLOG(HALF)) JHEP=JDAHEP(2,IHEP)
+ ELSEIF (IST.GT.112) THEN
+ IF ((ID.GT.6.AND.ID.LT.13).OR.
+ & (ID.GT.214.AND.ID.LT.221)) JHEP=JDAHEP(2,IHEP)
+ ELSE
+ IF (ID.LT.7.OR.(ID.GT.208.AND.ID.LT.215)) JHEP=JDAHEP(2,IHEP)
+ ENDIF
+ IF (JHEP.LE.0.OR.JHEP.GT.NHEP) THEN
+ CALL HWWARN('HWBGEN',1,*999)
+ JHEP=IHEP
+ ENDIF
+ JCOPAR(1,1)=JHEP
+ EINHEP=PHEP(4,IHEP)
+ ERTXI=HWULDO(PHEP(1,IHEP),PHEP(1,JHEP))
+ IF (ERTXI.LT.ZERO) ERTXI=0.
+ IF (IST.LE.112.AND.IHEP.EQ.JHEP) ERTXI=0.
+ IF (ISTHEP(JHEP).EQ.155) THEN
+ ERTXI=ERTXI/PHEP(5,JHEP)
+ RTXI=1.
+ ELSE
+ ERTXI=SQRT(ERTXI)
+ RTXI=ERTXI/EINHEP
+ ENDIF
+ IF (RTXI.EQ.ZERO) THEN
+ XF=1.
+ PPAR(1,1)=0.
+ PPAR(3,1)=1.
+ PPAR(1,2)=EINHEP
+ PPAR(2,2)=0.
+ PPAR(4,2)=EINHEP
+ ELSE
+ XF=1./RTXI
+ PPAR(1,1)=1.
+ PPAR(3,1)=0.
+ PPAR(1,2)=ERTXI
+ PPAR(2,2)=1.
+ PPAR(4,2)=ERTXI
+ ENDIF
+ IF (PPAR(4,2).LT.PHEP(5,IHEP)) PPAR(4,2)=PHEP(5,IHEP)
+C---STORE MASS
+ PPAR(5,2)=PHEP(5,IHEP)
+ CALL HWVZRO(4,VPAR(1,1))
+ CALL HWVZRO(4,VPAR(1,2))
+ IF (IST.GT.112) THEN
+ TMPAR(2)=.TRUE.
+ INHAD=0
+ JNHAD=0
+ XFACT=0.
+ ELSE
+ TMPAR(2)=.FALSE.
+ JNHAD=IST-110
+ INHAD=JNHAD
+ IF (JDAHEP(1,JNHAD).NE.0) INHAD=JDAHEP(1,JNHAD)
+ XFACT=XF/PHEP(4,INHAD)
+ ANOMSC(1,JNHAD)=ZERO
+ ANOMSC(2,JNHAD)=ZERO
+ ENDIF
+C---FOR QUARKS IN A COLOUR SINGLET, ALLOW SOFT MATRIX-ELEMENT CORRECTION
+ HARDST=PPAR(4,2)
+ IF (SOFTME.AND.IDHW(IHEP).LT.13.AND.
+ $ ((JMOHEP(2,JHEP).EQ.IHEP.AND.JDAHEP(2,JHEP).EQ.IHEP).OR.
+ $ ISTHEP(JHEP).EQ.155)) HARDST=0
+C---CREATE BRANCHES AND COMPUTE ENERGIES
+ DO 20 KPAR=2,NMXPAR
+ IF (TMPAR(KPAR)) THEN
+ CALL HWBRAN(KPAR)
+ ELSE
+ CALL HWSBRN(KPAR)
+ ENDIF
+ IF (IERROR.NE.0) RETURN
+ IF (FROST) GOTO 100
+ IF (KPAR.EQ.NPAR) GOTO 30
+ 20 CONTINUE
+C---COMPUTE MASSES AND 3-MOMENTA
+ 30 CONTINUE
+ CALL HWBMAS
+ IF (AZSPIN) CALL HWBSPN
+ IF (TMPAR(2)) THEN
+ CALL HWBTIM(2,1)
+ ELSE
+ CALL HWBSPA
+ ENDIF
+C---ENTER PARTON JET IN /HEPEVT/
+ CALL HWBFIN(IHEP)
+ ELSE
+C---COPY SPECTATOR
+ NHEP=NHEP+1
+ IF (ID.GT.120.AND.ID.LT.133 .OR. ID.GE.198.AND.ID.LE.201) THEN
+ ISTHEP(NHEP)=190
+ ELSE
+ ISTHEP(NHEP)=152
+ ENDIF
+ IDHW(NHEP)=ID
+ IDHEP(NHEP)=IDPDG(ID)
+ JMOHEP(1,NHEP)=IHEP
+ JMOHEP(2,NHEP)=0
+ JDAHEP(2,NHEP)=0
+ JDAHEP(1,IHEP)=NHEP
+ CALL HWVEQU(5,PHEP(1,IHEP),PHEP(1,NHEP))
+ ENDIF
+ ISTHEP(IHEP)=ISTHEP(IHEP)+10
+ ENDIF
+ 100 CONTINUE
+ IF (.NOT.FROST) THEN
+C---COMBINE JETS
+ ISTAT=20
+ CALL HWBJCO
+ ENDIF
+ IF (.NOT.FROST) THEN
+C---ATTACH SPECTATORS
+ ISTAT=30
+ CALL HWSSPC
+ ENDIF
+ IF (FROST) THEN
+C---BAD JET: RESTORE PARTONS AND RE-EVOLVE
+ DO 120 I=1,NRHEP
+ 120 ISTHEP(IRHEP(I))=IRST(I)
+ GOTO 10
+ ENDIF
+C---CONNECT COLOURS
+ CALL HWBCON
+ ISTAT=40
+ LASHEP=NHEP
+ IF (HARDME) THEN
+C---CLEAN UP IF THERE WAS A BRANCH IN THE `DEAD ZONE' IN E+E-
+ IF (IPROC/10.EQ.10) CALL HWBDED(2)
+C---CLEAN UP IF THERE WAS A BRANCH IN THE `DEAD ZONE' IN DIS
+ IF (IPRO.EQ.90) CALL HWBDIS(2)
+C---CLEAN UP IF THERE WAS A BRANCH IN THE `DEAD ZONE' IN DRELL-YAN PROC
+ IF (IPRO.EQ.13.OR.IPRO.EQ.14) CALL HWBDYP(2)
+ ENDIF
+C---IF THE CLEAN-UP OPERATION ADDED ANY PARTONS TO THE EVENT RECORD
+C IT MIGHT NEED RESHOWERING
+ IF (NHEP.GT.LASHEP) THEN
+ LASHEP=NHEP
+ GOTO 10
+ ENDIF
+ 999 END
+CDECK ID>, HWBJCO.
+*CMZ :- -26/04/91 14.25.31 by Federico Carminati
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBJCO
+C-----------------------------------------------------------------------
+C COMBINES JETS WITH REQUIRED KINEMATICS
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWULDO,EPS,PTX,PTY,PF,PTINF,PTCON,CN,CP,SP,PP0,
+ & PM0,ET0,DET,ECM,EMJ,EMP,EMS,DMS,ES,DPF,ALF,AL(2),ET(2),PP(2),
+ & PT(3),PB(5),PC(5),PQ(5),PR(5),PS(5),RR(3,3),RS(3,3),ETC,
+ & PJ(NMXJET),PM(NMXJET),PBR(5),RBR(3,3),DISP(4)
+ INTEGER LJET,IJ1,IST,IP,ICM,IP1,IP2,NP,IHEP,MHEP,JP,KP,LP,KHEP,
+ & JHEP,NE,IJT,IEND(2),IJET(NMXJET),IPAR(NMXJET)
+ LOGICAL AZCOR,JETRAD,DISPRO,DISLOW
+ EXTERNAL HWULDO
+ PARAMETER (EPS=1.D-4)
+ IF (IERROR.NE.0) RETURN
+ AZCOR=AZSOFT.OR.AZSPIN
+C---FIRST LOOK FOR SPACELIKE JETS
+ LJET=131
+ 10 IJET(1)=1
+ 20 IJ1=IJET(1)
+ DO 40 IHEP=IJ1,NHEP
+ IST=ISTHEP(IHEP)
+ IF (IST.EQ.137.OR.IST.EQ.138) IST=133
+ IF (IST.EQ.LJET) THEN
+C---FOUND AN UNBOOSTED JET - FIND PARTNERS
+ IP=JMOHEP(1,IHEP)
+ ICM=JMOHEP(1,IP)
+ DISPRO=IPRO/10.EQ.9.AND.IDHW(ICM).EQ.15
+ DISLOW=DISPRO.AND.JDAHEP(1,ICM).EQ.JDAHEP(2,ICM)-1
+ IF (IST.EQ.131) THEN
+ IP1=JMOHEP(1,ICM)
+ IP2=JMOHEP(2,ICM)
+ ELSE
+ IP1=JDAHEP(1,ICM)
+ IP2=JDAHEP(2,ICM)
+ ENDIF
+ IF (IP1.NE.IP) CALL HWWARN('HWBJCO',100,*999)
+ NP=0
+ DO 30 JHEP=IP1,IP2
+ NP=NP+1
+ IPAR(NP)=JHEP
+ 30 IJET(NP)=JDAHEP(1,JHEP)
+ GOTO 50
+ ENDIF
+ 40 CONTINUE
+C---NO MORE JETS?
+ IF (LJET.EQ.131) THEN
+ LJET=133
+ GOTO 10
+ ENDIF
+ RETURN
+ 50 IF (LJET.EQ.131) THEN
+C---SPACELIKE JETS: FIND SPACELIKE PARTONS
+ IF (NP.NE.2) CALL HWWARN('HWBJCO',103,*999)
+C---special for DIS: FIND BOOST AND ROTATION FROM LAB TO BREIT FRAME
+ IF (DISPRO.AND.BREIT) THEN
+ IP=2
+ IF (JDAHEP(1,IP).NE.0) IP=JDAHEP(1,IP)
+ CALL HWVDIF(4,PHEP(1,JMOHEP(1,ICM)),PHEP(1,JDAHEP(1,ICM)),PB)
+ CALL HWUMAS(PB)
+C---IF Q**2<10**-2, SOMETHING MUST HAVE ALREADY GONE WRONG
+ IF (PB(5)**2.LT.1.D-2) CALL HWWARN('HWBJCO',102,*999)
+ CALL HWVSCA(4,PB(5)**2/HWULDO(PHEP(1,IP),PB),PHEP(1,IP),PBR)
+ CALL HWVSUM(4,PB,PBR,PBR)
+ CALL HWUMAS(PBR)
+ CALL HWULOF(PBR,PB,PB)
+ CALL HWUROT(PB,ONE,ZERO,RBR)
+ ENDIF
+ PTX=0.
+ PTY=0.
+ PF=1.D0
+ DO 90 IP=1,2
+ MHEP=IJET(IP)
+ IF (JDAHEP(1,MHEP).EQ.0) THEN
+C---SPECIAL FOR NON-PARTON JETS
+ IHEP=MHEP
+ GOTO 70
+ ELSE
+ IST=134+IP
+ DO 60 IHEP=MHEP,NHEP
+ 60 IF (ISTHEP(IHEP).EQ.IST) GOTO 70
+C---COULDN'T FIND SPACELIKE PARTON
+ CALL HWWARN('HWBJCO',101,*999)
+ ENDIF
+ 70 CALL HWVSCA(3,PF,PHEP(1,IHEP),PS)
+ IF (PTINT(3,IP).GT.ZERO) THEN
+C---ADD INTRINSIC PT
+ PT(1)=PTINT(1,IP)
+ PT(2)=PTINT(2,IP)
+ PT(3)=0.
+ CALL HWUROT(PS, ONE,ZERO,RS)
+ CALL HWUROB(RS,PT,PT)
+ CALL HWVSUM(3,PS,PT,PS)
+ ENDIF
+ JP=IJET(IP)+1
+ IF (AZCOR.AND.JP.LE.NHEP.AND.IDHW(JP).EQ.17) THEN
+C---ALIGN CONE WITH INTERFERING PARTON
+ CALL HWUROT(PS, ONE,ZERO,RS)
+ CALL HWUROF(RS,PHEP(1,JP),PR)
+ PTCON=PR(1)**2+PR(2)**2
+ KP=JMOHEP(2,JP)
+ IF (KP.EQ.0) THEN
+ CALL HWWARN('HWBJCO',1,*999)
+ PTINF=0.
+ ELSE
+ CALL HWVEQU(4,PHEP(1,KP),PB)
+ IF (DISPRO.AND.BREIT) THEN
+ CALL HWULOF(PBR,PB,PB)
+ CALL HWUROF(RBR,PB,PB)
+ ENDIF
+ PTINF=PB(1)**2+PB(2)**2
+ IF (PTINF.LT.EPS) THEN
+C---COLLINEAR JETS: ALIGN CONES
+ KP=JDAHEP(1,KP)+1
+ IF (ISTHEP(KP).EQ.100.AND.ISTHEP(KP-1)/10.EQ.14) THEN
+ CALL HWVEQU(4,PHEP(1,KP),PB)
+ IF (DISPRO.AND.BREIT) THEN
+ CALL HWULOF(PBR,PB,PB)
+ CALL HWUROF(RBR,PB,PB)
+ ENDIF
+ PTINF=PB(1)**2+PB(2)**2
+ ELSE
+ PTINF=0.
+ ENDIF
+ ENDIF
+ ENDIF
+ IF (PTCON.NE.ZERO.AND.PTINF.NE.ZERO) THEN
+ CN=1./SQRT(PTINF*PTCON)
+ CP=CN*(PR(1)*PB(1)+PR(2)*PB(2))
+ SP=CN*(PR(1)*PB(2)-PR(2)*PB(1))
+ ELSE
+ CALL HWRAZM( ONE,CP,SP)
+ ENDIF
+ ELSE
+ CALL HWRAZM( ONE,CP,SP)
+ ENDIF
+C---ROTATE SO SPACELIKE IS ALONG AXIS (APART FROM INTRINSIC PT)
+ CALL HWUROT(PS,CP,SP,RS)
+ IHEP=IJET(IP)
+ KHEP=JDAHEP(2,IHEP)
+ IF (KHEP.LT.IHEP) KHEP=IHEP
+ IEND(IP)=KHEP
+ DO 80 JHEP=IHEP,KHEP
+ CALL HWUROF(RS,PHEP(1,JHEP),PHEP(1,JHEP))
+ 80 CALL HWUROF(RS,VHEP(1,JHEP),VHEP(1,JHEP))
+ PP(IP)=PHEP(4,IHEP)+PF*PHEP(3,IHEP)
+ ET(IP)=PHEP(1,IHEP)**2+PHEP(2,IHEP)**2-PHEP(5,IHEP)**2
+C---REDEFINE HARD CM
+ PTX=PTX+PHEP(1,IHEP)
+ PTY=PTY+PHEP(2,IHEP)
+ 90 PF=-PF
+ PHEP(1,ICM)=PTX
+ PHEP(2,ICM)=PTY
+C---special for DIS: keep lepton momenta fixed
+ IF (DISPRO) THEN
+ IP1=JMOHEP(1,ICM)
+ IP2=JDAHEP(1,ICM)
+ IJT=IJET(1)
+C---IJT will be used to store lepton momentum transfer
+ CALL HWVDIF(4,PHEP(1,IP1),PHEP(1,IP2),PHEP(1,IJT))
+ CALL HWUMAS(PHEP(1,IJT))
+ IF (IDHEP(IP1).EQ.IDHEP(IP2)) THEN
+ IDHW(IJT)=200
+ ELSEIF (IDHEP(IP1).LT.IDHEP(IP2)) THEN
+ IDHW(IJT)=199
+ ELSE
+ IDHW(IJT)=198
+ ENDIF
+ IDHEP(IJT)=IDPDG(IDHW(IJT))
+ ISTHEP(IJT)=3
+C---calculate boost for struck parton
+C PC is momentum of outgoing parton(s)
+ IP2=JDAHEP(2,ICM)
+ IF (.NOT.DISLOW) THEN
+C---FOR heavy QQbar PQ and PC are old and new QQbar momenta
+ CALL HWVSUM(4,PHEP(1,IP2-1),PHEP(1,IP2),PQ)
+ CALL HWUMAS(PQ)
+ PC(5)=PQ(5)
+ ELSE
+ PC(5)=PHEP(5,JDAHEP(1,IP2))
+ ENDIF
+ CALL HWVSUM(2,PHEP(1,IJT),PHEP(1,IJET(2)),PC)
+ ET(1)=ET(2)
+C---USE BREIT FRAME BOSON MOMENTUM IF NECESSARY
+ IF (BREIT) THEN
+ ET(2)=ET(1)+PC(5)**2+PHEP(5,IJET(2))**2
+ PM0=PHEP(5,IJT)
+ PP0=-PM0
+ ELSE
+ ET(2)=PC(1)**2+PC(2)**2+PC(5)**2
+ PP0=PHEP(4,IJT)+PHEP(3,IJT)
+ PM0=PHEP(4,IJT)-PHEP(3,IJT)
+ ENDIF
+ ET0=(PP0*PM0)+ET(1)-ET(2)
+ DET=ET0**2-4.*(PP0*PM0)*ET(1)
+ IF (DET.LT.ZERO) THEN
+ FROST=.TRUE.
+ RETURN
+ ENDIF
+ ALF=(SQRT(DET)-ET0)/(2.*PP0*PP(2))
+ PB(1)=0.
+ PB(2)=0.
+ PB(5)=2.D0
+ PB(3)=ALF-(1./ALF)
+ PB(4)=ALF+(1./ALF)
+ DO 100 IHEP=IJET(2),IEND(2)
+ CALL HWULOF(PB,PHEP(1,IHEP),PHEP(1,IHEP))
+ CALL HWULF4(PB,VHEP(1,IHEP),VHEP(1,IHEP))
+C---BOOST FROM BREIT FRAME IF NECESSARY
+ IF (BREIT) THEN
+ CALL HWUROB(RBR,PHEP(1,IHEP),PHEP(1,IHEP))
+ CALL HWULOB(PBR,PHEP(1,IHEP),PHEP(1,IHEP))
+ CALL HWUROB(RBR,VHEP(1,IHEP),VHEP(1,IHEP))
+ CALL HWULB4(PBR,VHEP(1,IHEP),VHEP(1,IHEP))
+ ENDIF
+ 100 ISTHEP(IHEP)=ISTHEP(IHEP)+10
+ CALL HWVDIF(4,VHEP(1,IPAR(2)),VHEP(1,IJET(2)),DISP)
+ DO 110 IHEP=IJET(2),IEND(2)
+ 110 CALL HWVSUM(4,DISP,VHEP(1,IHEP),VHEP(1,IHEP))
+ IF (IEND(2).GT.IJET(2)+1) ISTHEP(IJET(2)+1)=100
+ CALL HWVSUM(4,PHEP(1,IJT),PHEP(1,IJET(2)),PC)
+ CALL HWVSUM(4,PHEP(1,IP1),PHEP(1,IJET(2)),PHEP(1,ICM))
+ CALL HWUMAS(PHEP(1,ICM))
+ ELSEIF (IPRO/10.EQ.5) THEN
+C Special to preserve photon momentum
+ ETC=PTX**2+PTY**2+PHEP(5,ICM)**2
+ ET0=ETC+ET(1)-ET(2)
+ DET=ET0**2-4.*ETC*ET(1)
+ IF (DET.LT.ZERO) THEN
+ FROST=.TRUE.
+ RETURN
+ ENDIF
+ ALF=(SQRT(DET)+ET0-2.*ET(1))/(2.*PP(1)*PP(2))
+ PB(1)=0.
+ PB(2)=0.
+ PB(3)=ALF-1./ALF
+ PB(4)=ALF+1./ALF
+ PB(5)=2.
+ IJT=IJET(2)
+ DO 120 IHEP=IJT,IEND(2)
+ CALL HWULOF(PB,PHEP(1,IHEP),PHEP(1,IHEP))
+ CALL HWULF4(PB,VHEP(1,IHEP),VHEP(1,IHEP))
+ 120 ISTHEP(IHEP)=ISTHEP(IHEP)+10
+ CALL HWVDIF(4,VHEP(1,IPAR(2)),VHEP(1,IJT),DISP)
+ DO 130 IHEP=IJT,IEND(2)
+ 130 CALL HWVSUM(4,DISP,VHEP(1,IHEP),VHEP(1,IHEP))
+ IF (IEND(2).GT.IJT+1) ISTHEP(IJT+1)=100
+ ISTHEP(IJET(1))=ISTHEP(IJET(1))+10
+ CALL HWVSUM(2,PHEP(3,IPAR(1)),PHEP(3,IJT),PHEP(3,ICM))
+ ELSE
+ PHEP(4,ICM)=SQRT(PTX**2+PTY**2+PHEP(3,ICM)**2+PHEP(5,ICM)**2)
+C---NOW BOOST TO REQUIRED Q**2 AND X-F
+ PP0=PHEP(4,ICM)+PHEP(3,ICM)
+ PM0=PHEP(4,ICM)-PHEP(3,ICM)
+ ET0=(PP0*PM0)+ET(1)-ET(2)
+ DET=ET0**2-4.*(PP0*PM0)*ET(1)
+ IF (DET.LT.ZERO) THEN
+ FROST=.TRUE.
+ RETURN
+ ENDIF
+ DET=SQRT(DET)+ET0
+ AL(1)= 2.*PM0*PP(1)/DET
+ AL(2)=(PM0/PP(2))*(1.-2.*ET(1)/DET)
+ PB(1)=0.
+ PB(2)=0.
+ PB(5)=2.
+ DO 160 IP=1,2
+ PB(3)=AL(IP)-(1./AL(IP))
+ PB(4)=AL(IP)+(1./AL(IP))
+ IJT=IJET(IP)
+ DO 140 IHEP=IJT,IEND(IP)
+ CALL HWULOF(PB,PHEP(1,IHEP),PHEP(1,IHEP))
+ CALL HWULF4(PB,VHEP(1,IHEP),VHEP(1,IHEP))
+ 140 ISTHEP(IHEP)=ISTHEP(IHEP)+10
+ CALL HWVDIF(4,VHEP(1,IPAR(IP)),VHEP(1,IJT),DISP)
+ DO 150 IHEP=IJT,IEND(IP)
+ 150 CALL HWVSUM(4,DISP,VHEP(1,IHEP),VHEP(1,IHEP))
+ IF (IEND(IP).GT.IJT+1) THEN
+ ISTHEP(IJT+1)=100
+ ELSEIF (IEND(IP).EQ.IJT) THEN
+C---NON-PARTON JET
+ ISTHEP(IJT)=3
+ ENDIF
+ 160 CONTINUE
+ ENDIF
+ ISTHEP(ICM)=120
+ ELSE
+C---TIMELIKE JETS
+C special for DIS: preserve outgoing lepton momentum
+ IF (DISPRO) THEN
+ CALL HWVEQU(5,PHEP(1,IPAR(1)),PHEP(1,IJET(1)))
+ ISTHEP(IJET(1))=1
+ LP=2
+ ELSE
+ CALL HWVEQU(5,PHEP(1,ICM),PC)
+C--- PQ AND PC ARE OLD AND NEW PARTON CM
+ CALL HWVSUM(4,PHEP(1,IPAR(1)),PHEP(1,IPAR(2)),PQ)
+ PQ(5)=PHEP(5,ICM)
+ IF (NP.GT.2) THEN
+ DO 170 KP=3,NP
+ 170 CALL HWVSUM(4,PHEP(1,IPAR(KP)),PQ,PQ)
+ ENDIF
+ LP=1
+ ENDIF
+ IF (.NOT.DISLOW) THEN
+C---FIND JET CM MOMENTA
+ ECM=PQ(5)
+ EMS=0.
+ JETRAD=.FALSE.
+ DO 180 KP=LP,NP
+ EMJ=PHEP(5,IJET(KP))
+ EMP=PHEP(5,IPAR(KP))
+ JETRAD=JETRAD.OR.EMJ.NE.EMP
+ EMS=EMS+EMJ
+ PM(KP)= EMJ**2
+C---N.B. ROUNDING ERRORS HERE AT HIGH ENERGIES
+ PJ(KP)=(HWULDO(PHEP(1,IPAR(KP)),PQ)/ECM)**2-EMP**2
+ IF (PJ(KP).LE.ZERO) CALL HWWARN('HWBJCO',104,*999)
+ 180 CONTINUE
+ PF=1.
+ IF (JETRAD) THEN
+C---JETS DID RADIATE
+ IF (EMS.GE.ECM) THEN
+ FROST=.TRUE.
+ RETURN
+ ENDIF
+ DO 200 NE=1,NETRY
+ EMS=-ECM
+ DMS=0.
+ DO 190 KP=LP,NP
+ ES=SQRT(PF*PJ(KP)+PM(KP))
+ EMS=EMS+ES
+ 190 DMS=DMS+PJ(KP)/ES
+ DPF=2.*EMS/DMS
+ IF (DPF.GT.PF) DPF=0.9*PF
+ PF=PF-DPF
+ 200 IF (ABS(DPF).LT.EPS) GOTO 210
+ CALL HWWARN('HWBJCO',105,*999)
+ ENDIF
+ 210 CONTINUE
+ ENDIF
+C---BOOST PC AND PQ TO BREIT FRAME IF NECESSARY
+ IF (DISPRO.AND.BREIT) THEN
+ CALL HWULOF(PBR,PC,PC)
+ CALL HWUROF(RBR,PC,PC)
+ IF (.NOT.DISLOW) THEN
+ CALL HWULOF(PBR,PQ,PQ)
+ CALL HWUROF(RBR,PQ,PQ)
+ ENDIF
+ ENDIF
+ DO 230 IP=LP,NP
+C---FIND CM ROTATION FOR JET IP
+ IF (.NOT.DISLOW) THEN
+ CALL HWVEQU(4,PHEP(1,IPAR(IP)),PR)
+ IF (DISPRO.AND.BREIT) THEN
+ CALL HWULOF(PBR,PR,PR)
+ CALL HWUROF(RBR,PR,PR)
+ ENDIF
+ CALL HWULOF(PQ,PR,PR)
+ CALL HWUROT(PR, ONE,ZERO,RR)
+ PR(1)=0.
+ PR(2)=0.
+ PR(3)=SQRT(PF*PJ(IP))
+ PR(4)=SQRT(PF*PJ(IP)+PM(IP))
+ PR(5)=PHEP(5,IJET(IP))
+ CALL HWUROB(RR,PR,PR)
+ CALL HWULOB(PC,PR,PR)
+ ELSE
+ CALL HWVEQU(5,PC,PR)
+ ENDIF
+C---NOW PR IS LAB/BREIT MOMENTUM OF JET IP
+ KP=IJET(IP)+1
+ IF (AZCOR.AND.KP.LE.NHEP.AND.IDHW(KP).EQ.17) THEN
+C---ALIGN CONE WITH INTERFERING PARTON
+ CALL HWUROT(PR, ONE,ZERO,RS)
+ JP=JMOHEP(2,KP)
+ IF (JP.EQ.0) THEN
+ CALL HWWARN('HWBJCO',2,*999)
+ PTINF=0.
+ ELSE
+ CALL HWVEQU(4,PHEP(1,JP),PS)
+ IF (DISPRO.AND.BREIT) THEN
+ CALL HWULOF(PBR,PS,PS)
+ CALL HWUROF(RBR,PS,PS)
+ ENDIF
+ CALL HWUROF(RS,PS,PS)
+ PTINF=PS(1)**2+PS(2)**2
+ IF (PTINF.LT.EPS) THEN
+C---COLLINEAR JETS: ALIGN CONES
+ JP=JDAHEP(1,JP)+1
+ IF (ISTHEP(JP).EQ.100.AND.ISTHEP(JP-1)/10.EQ.14) THEN
+ CALL HWVEQU(4,PHEP(1,JP),PS)
+ IF (DISPRO.AND.BREIT) THEN
+ CALL HWULOF(PBR,PS,PS)
+ CALL HWUROF(RBR,PS,PS)
+ ENDIF
+ CALL HWUROF(RS,PS,PS)
+ PTINF=PS(1)**2+PS(2)**2
+ ELSE
+ PTINF=0.
+ ENDIF
+ ENDIF
+ ENDIF
+ CALL HWVEQU(4,PHEP(1,KP),PB)
+ IF (DISPRO.AND.BREIT) THEN
+ CALL HWULOF(PBR,PB,PB)
+ CALL HWUROF(RBR,PB,PB)
+ ENDIF
+ PTCON=PB(1)**2+PB(2)**2
+ IF (PTCON.NE.ZERO.AND.PTINF.NE.ZERO) THEN
+ CN=1./SQRT(PTINF*PTCON)
+ CP=CN*(PS(1)*PB(1)+PS(2)*PB(2))
+ SP=CN*(PS(1)*PB(2)-PS(2)*PB(1))
+ ELSE
+ CALL HWRAZM( ONE,CP,SP)
+ ENDIF
+ ELSE
+ CALL HWRAZM( ONE,CP,SP)
+ ENDIF
+ CALL HWUROT(PR,CP,SP,RS)
+C---FIND BOOST FOR JET IP
+ ALF=(PHEP(3,IJET(IP))+PHEP(4,IJET(IP)))/
+ & (PR(4)+SQRT((PR(4)+PR(5))*(PR(4)-PR(5))))
+ PB(1)=0.
+ PB(2)=0.
+ PB(3)=ALF-(1./ALF)
+ PB(4)=ALF+(1./ALF)
+ PB(5)=2.
+ IHEP=IJET(IP)
+ KHEP=JDAHEP(2,IHEP)
+ IF (KHEP.LT.IHEP) KHEP=IHEP
+ DO 220 JHEP=IHEP,KHEP
+ CALL HWULOF(PB,PHEP(1,JHEP),PHEP(1,JHEP))
+ CALL HWUROB(RS,PHEP(1,JHEP),PHEP(1,JHEP))
+ CALL HWULF4(PB,VHEP(1,JHEP),VHEP(1,JHEP))
+ CALL HWUROB(RS,VHEP(1,JHEP),VHEP(1,JHEP))
+C---BOOST FROM BREIT FRAME IF NECESSARY
+ IF (DISPRO.AND.BREIT) THEN
+ CALL HWUROB(RBR,PHEP(1,JHEP),PHEP(1,JHEP))
+ CALL HWULOB(PBR,PHEP(1,JHEP),PHEP(1,JHEP))
+ CALL HWUROB(RBR,VHEP(1,JHEP),VHEP(1,JHEP))
+ CALL HWULB4(PBR,VHEP(1,JHEP),VHEP(1,JHEP))
+ ENDIF
+ CALL HWVSUM(4,VHEP(1,JHEP),VHEP(1,IPAR(IP)),VHEP(1,JHEP))
+ 220 ISTHEP(JHEP)=ISTHEP(JHEP)+10
+ IF (KHEP.GT.IHEP+1) THEN
+ ISTHEP(IHEP+1)=100
+ ELSEIF (KHEP.EQ.IHEP) THEN
+C---NON-PARTON JET
+ ISTHEP(IHEP)=190
+ ENDIF
+ 230 CONTINUE
+ IF (ISTHEP(ICM).EQ.110) ISTHEP(ICM)=120
+ ENDIF
+ GOTO 20
+ 999 END
+CDECK ID>, HWBMAS.
+*CMZ :- -26/04/91 11.11.54 by Bryan Webber
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBMAS
+C-----------------------------------------------------------------------
+C Passes backwards through a jet cascade calculating the masses
+C and magnitudes of the longitudinal and transverse three momenta.
+C Components given relative to direction of parent for a time-like
+C vertex and with respect to z-axis for space-like vertices.
+C
+C On input PPAR(1-5,*) contains:
+C (E*sqrt(Xi),Xi,3-mom (if external),E,M-sq (if external))
+C
+C On output PPAR(1-5,*) (if TMPAR(*)), containts:
+C (P-trans,Xi or Xilast,P-long,E,M)
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWUSQR,EXI,PISQ,PJPK,EJEK,PTSQ,Z,ZMIN,ZMAX,
+ $ EMI,EMJ,EMK,C,NQ,HWBVMC,RHO,POLD,PNEW,EOLD,ENEW,A,B
+ INTEGER IPAR,JPAR,KPAR,MPAR,I,J,K
+ EXTERNAL HWUSQR
+ IF (IERROR.NE.0) RETURN
+ IF (NPAR.GT.2) THEN
+ DO 30 MPAR=NPAR-1,3,-2
+ JPAR=MPAR
+C Find parent and partner of this branch
+ IPAR=JMOPAR(1,JPAR)
+ KPAR=JPAR+1
+C Determine type of branching
+ IF (TMPAR(IPAR)) THEN
+C Time-like branching
+C Compute mass of parent
+ EXI=PPAR(1,JPAR)*PPAR(1,KPAR)
+ PPAR(5,IPAR)=PPAR(5,JPAR)+PPAR(5,KPAR)+2.*EXI
+C Compute three momentum of parent
+ PISQ=PPAR(4,IPAR)*PPAR(4,IPAR)-PPAR(5,IPAR)
+ PPAR(3,IPAR)=HWUSQR(PISQ)
+C---SPECIAL FOR G-->QQBAR: READJUST ANGULAR DISTRIBUTION
+ IF (IDPAR(IPAR).EQ.13 .AND. IDPAR(JPAR).LT.13) THEN
+ Z=PPAR(4,JPAR)/PPAR(4,IPAR)
+ ZMIN=HWBVMC(IDPAR(JPAR))/PPAR(1,JPAR)*Z
+ RHO=(Z*(3-Z*(3-2*Z))-ZMIN*(3-ZMIN*(3-2*ZMIN)))
+ $ /(2*(1-2*ZMIN)*(1-ZMIN*(1-ZMIN)))
+ NQ=PPAR(3,IPAR)*(PPAR(3,IPAR)+PPAR(4,IPAR))
+ EMI=PPAR(5,IPAR)
+ EMJ=PPAR(5,JPAR)
+ EMK=PPAR(5,KPAR)
+ ZMIN=MAX((EMI+EMJ-EMK)/(2*(EMI+NQ)),
+ $ (EMI+EMJ-EMK-SQRT((EMI-EMJ-EMK)**2-4*EMJ*EMK))/(2*EMI))
+ ZMAX=1-MAX((EMI-EMJ+EMK)/(2*(EMI+NQ)),
+ $ (EMI-EMJ+EMK-SQRT((EMI-EMJ-EMK)**2-4*EMJ*EMK))/(2*EMI))
+ C=2*RMASS(IDPAR(JPAR))**2/EMI
+ Z=(4*ZMIN*(1.5*(1+C-ZMIN)+ZMIN**2)*(1-RHO)
+ $ +4*ZMAX*(1.5*(1+C-ZMAX)+ZMAX**2)*RHO-2-3*C)/(1+2*C)**1.5
+ Z=SQRT(1+2*C)*SINH(LOG(Z+SQRT(Z**2+1))/3)+0.5
+ Z=(Z*NQ+(EMI+EMJ-EMK)/2)/(NQ+EMI)
+ PPAR(4,JPAR)=Z*PPAR(4,IPAR)
+ PPAR(4,KPAR)=PPAR(4,IPAR)-PPAR(4,JPAR)
+ PPAR(3,JPAR)=HWUSQR(PPAR(4,JPAR)**2-EMJ)
+ PPAR(3,KPAR)=HWUSQR(PPAR(4,KPAR)**2-EMK)
+ PPAR(2,JPAR)=EXI/(PPAR(4,JPAR)*PPAR(4,KPAR))
+ IF(JDAPAR(2,JPAR).NE.0)PPAR(2,JDAPAR(2,JPAR))=PPAR(2,JPAR)
+ IF(JDAPAR(2,KPAR).NE.0)PPAR(2,JDAPAR(2,KPAR))=PPAR(2,JPAR)
+C---FIND DESCENDENTS OF THIS SPLITTING AND READJUST THEIR MOMENTA TOO
+ DO 20 J=JPAR+2,NPAR-1,2
+ I=J
+ 10 I=JMOPAR(1,I)
+ IF (I.GT.IPAR) GOTO 10
+ IF (I.EQ.IPAR) THEN
+ I=JMOPAR(1,J)
+ K=J+1
+ POLD=PPAR(3,J)+PPAR(3,K)
+ EOLD=PPAR(4,J)+PPAR(4,K)
+ PNEW=HWUSQR(PPAR(4,I)**2-PPAR(5,I))
+ ENEW=PPAR(4,I)
+ A=(ENEW*EOLD-PNEW*POLD)/PPAR(5,I)
+ B=(PNEW*EOLD-ENEW*POLD)/PPAR(5,I)
+ PPAR(3,J)=A*PPAR(3,J)+B*PPAR(4,J)
+ PPAR(4,J)=(PPAR(4,J)+B*PPAR(3,J))/A
+ PPAR(3,K)=PNEW-PPAR(3,J)
+ PPAR(4,K)=ENEW-PPAR(4,J)
+ PPAR(2,J)=1-(PPAR(3,J)*PPAR(3,K)+PPAR(1,J)*PPAR(1,K))
+ $ /(PPAR(4,J)*PPAR(4,K))
+ IF (JDAPAR(2,J).NE.0) PPAR(2,JDAPAR(2,J))=PPAR(2,J)
+ IF (JDAPAR(2,K).NE.0) PPAR(2,JDAPAR(2,K))=PPAR(2,J)
+ ENDIF
+ 20 CONTINUE
+ ENDIF
+C Compute daughter' transverse and longitudinal momenta
+ PJPK=PPAR(3,JPAR)*PPAR(3,KPAR)
+ EJEK=PPAR(4,JPAR)*PPAR(4,KPAR)-EXI
+ PTSQ=(PJPK+EJEK)*(PJPK-EJEK)/PISQ
+ PPAR(1,JPAR)=HWUSQR(PTSQ)
+ PPAR(3,JPAR)=HWUSQR(PPAR(3,JPAR)*PPAR(3,JPAR)-PTSQ)
+ PPAR(1,KPAR)=-PPAR(1,JPAR)
+ PPAR(3,KPAR)= PPAR(3,IPAR)-PPAR(3,JPAR)
+ ELSE
+C Space-like branching
+C Re-arrange such that JPAR is time-like
+ IF (TMPAR(KPAR)) THEN
+ KPAR=JPAR
+ JPAR=JPAR+1
+ ENDIF
+C Compute time-like branch
+ PTSQ=(2.-PPAR(2,JPAR))*PPAR(1,JPAR)*PPAR(1,JPAR)
+ & -PPAR(5,JPAR)
+ PPAR(1,JPAR)=HWUSQR(PTSQ)
+ PPAR(3,JPAR)=(1.-PPAR(2,JPAR))*PPAR(4,JPAR)
+ PPAR(3,IPAR)=PPAR(3,KPAR)-PPAR(3,JPAR)
+ PPAR(5,IPAR)=0.
+ PPAR(1,KPAR)=0.
+ ENDIF
+C Reset Xi to Xilast
+ PPAR(2,KPAR)=PPAR(2,IPAR)
+ 30 CONTINUE
+ ENDIF
+ DO 40 IPAR=2,NPAR
+ 40 PPAR(5,IPAR)=HWUSQR(PPAR(5,IPAR))
+ PPAR(1,2)=0.
+ PPAR(2,2)=0.
+ END
+CDECK ID>, HWBRAN.
+*CMZ :- -14/10/99 18.04.56 by Mike Seymour
+*-- Author : Bryan Webber & Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBRAN(KPAR)
+C-----------------------------------------------------------------------
+C BRANCHES TIMELIKE PARTON KPAR INTO TWO, PUTS PRODUCTS
+C INTO NPAR+1 AND NPAR+2, AND INCREASES NPAR BY TWO
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWBVMC,HWR,HWUALF,HWUTAB,HWRUNI,HWULDO,PMOM,
+ & QNOW,QLST,QKTHR,RN,QQBAR,DQQ,QGTHR,SNOW,QSUD,ZMIN,ZMAX,ZRAT,WMIN,
+ & QLAM,Z1,Z2,ETEST,ZTEST,ENOW,XI,XIPREV,EPREV,QMAX,QGAM,SLST,SFNL,
+ & TARG,ALF,BETA0(3:6),BETAP(3:6),SQRK(4:6,5),REJFAC,Z,X1,X2,OTHXI,
+ & OTHZ,X3,FF,AW,XCUT,CC,JJ,HWUSQR
+ INTEGER HWRINT,KPAR,ID,JD,IS,NTRY,N,ID1,ID2,MPAR,ISUD(13),IHEP,
+ & JHEP,M,NF,NN,IREJ,NREJ,ITOP
+ EXTERNAL HWBVMC,HWR,HWUALF,HWUTAB,HWRUNI,HWULDO,HWRINT,HWUSQR
+ SAVE BETA0,BETAP,SQRK
+ DATA ISUD,BETA0/2,2,3,4,5,6,2,2,3,4,5,6,1,4*ZERO/
+ IF (IERROR.NE.0) RETURN
+C---SET SQRK(M,N) TO THE PROBABILITY THAT A GLUON WILL NOT PRODUCE A
+C QUARK-ANTIQUARK PAIR BETWEEN SCALES RMASS(M) AND 2*HWBVMC(N)
+ IF (SUDORD.NE.1.AND.BETA0(3).EQ.ZERO) THEN
+ DO 100 M=3,6
+ BETA0(M)=(11.*CAFAC-2.*M)*0.5
+ 100 BETAP(M)=(17.*CAFAC**2-(5.*CAFAC+3.*CFFAC)*M)
+ & /BETA0(M)*0.25/PIFAC
+ DO 120 N=1,5
+ DO 110 M=4,6
+ IF (M.LE.N) THEN
+ SQRK(M,N)=ONE
+ ELSEIF (M.EQ.4.OR.M.EQ.N+1) THEN
+ NF=M
+ IF (2*HWBVMC(N).GT.RMASS(M)) NF=M+1
+ SQRK(M,N)=((BETAP(NF-1)+1/HWUALF(1,2*HWBVMC(N)))/
+ $ (BETAP(NF-1)+1/HWUALF(1,RMASS(M))))**(1/BETA0(NF-1))
+ ELSE
+ SQRK(M,N)=SQRK(M-1,N)*
+ $ ((BETAP(M-1)+1/HWUALF(1,RMASS(M-1)))/
+ $ (BETAP(M-1)+1/HWUALF(1,RMASS(M))))**(1/BETA0(M-1))
+ ENDIF
+ 110 CONTINUE
+ 120 CONTINUE
+ ENDIF
+ ID=IDPAR(KPAR)
+C--TEST FOR PARTON TYPE
+ IF (ID.LE.13) THEN
+ JD=ID
+ IS=ISUD(ID)
+ ELSEIF (ID.GE.209.AND.ID.LE.220) THEN
+ JD=ID-208
+ IS=7
+ ELSE
+ IS=0
+ END IF
+ QNOW=-1.
+ IF (IS.NE.0) THEN
+C--TIMELIKE PARTON BRANCHING
+ ENOW=PPAR(4,KPAR)
+ XIPREV=PPAR(2,KPAR)
+ IF (JMOPAR(1,KPAR).EQ.0) THEN
+ EPREV=PPAR(4,KPAR)
+ ELSE
+ EPREV=PPAR(4,JMOPAR(1,KPAR))
+ ENDIF
+C--IF THIS IS CHARGED & PHOTONS ARE ALLOWED, ANGLES MIGHT NOT BE ORDERED
+ QMAX=0
+ QLST=PPAR(1,KPAR)
+ IF (ICHRG(ID).NE.0 .AND. VPCUT.LT.PPAR(1,2)) THEN
+C--LOOK FOR A PREVIOUS G->QQBAR, IF ANY
+ MPAR=KPAR
+ 1 IF (JMOPAR(1,MPAR).NE.0) THEN
+ IF (IDPAR(JMOPAR(1,MPAR)).EQ.ID) THEN
+ MPAR=JMOPAR(1,MPAR)
+ GOTO 1
+ ENDIF
+ ENDIF
+C--IF CLIMBED TO THE TOP OF THE LIST, FIND QED INTERFERENCE PARTNER
+ IF (MPAR.EQ.2) THEN
+ JHEP=0
+ IF (ID.LT.7) THEN
+ IHEP=JDAHEP(2,JCOPAR(1,1))
+ IF (IHEP.GT.0) JHEP=JDAHEP(2,IHEP)
+ ELSE
+ IHEP=JMOHEP(2,JCOPAR(1,1))
+ IF (IHEP.GT.0) JHEP=JMOHEP(2,IHEP)
+ ENDIF
+ IF (IHEP.GT.0.AND.JHEP.GT.0) THEN
+ QMAX=HWULDO(PHEP(1,IHEP),PHEP(1,JHEP))
+ & *(ENOW/PPAR(4,2))**2
+ ELSE
+C--FIX AT HARD PROCESS SCALE IF POINTER NOT YET SET
+C (CAN HAPPEN IN SUSY EVENTS)
+ QMAX=EMSCA**2
+ ENDIF
+ ELSE
+ QMAX=ENOW**2*PPAR(2,MPAR)
+ ENDIF
+C--IF PREVIOUS BRANCHING WAS Q->QGAMMA, LOOK FOR A QCD BRANCHING
+ MPAR=KPAR
+ 2 IF (JMOPAR(1,MPAR).NE.0) THEN
+ IF (IDPAR(JDAPAR(1,JMOPAR(1,MPAR))).EQ.59 .OR.
+ & IDPAR(JDAPAR(2,JMOPAR(1,MPAR))).EQ.59) THEN
+ MPAR=JMOPAR(1,MPAR)
+ GOTO 2
+ ENDIF
+ ENDIF
+ QLST=ENOW**2*PPAR(2,MPAR)
+ QMAX=SQRT(MAX(ZERO,MIN(
+ & QMAX , EPREV**2*XIPREV , ENOW**2*XIPREV*(2-XIPREV))))
+ QLST=SQRT(MIN(
+ & QLST , EPREV**2*XIPREV , ENOW**2*XIPREV*(2-XIPREV)))
+ ENDIF
+ NTRY=0
+ 5 NTRY=NTRY+1
+ IF (NTRY.GT.NBTRY) CALL HWWARN('HWBRAN',100,*999)
+ IF (ID.EQ.13) THEN
+C--GLUON -> QUARK+ANTIQUARK OPTION
+ IF (QLST.GT.QCDL3) THEN
+ DO 8 N=1,NFLAV
+ QKTHR=2.*HWBVMC(N)
+ IF (QLST.GT.QKTHR) THEN
+ RN=HWR()
+ IF (SUDORD.NE.1) THEN
+C---FIND IN WHICH FLAVOUR INTERVAL THE UPPER LIMIT LIES
+ NF=3
+ DO 200 M=MAX(3,N),NFLAV
+ 200 IF (QLST.GT.RMASS(M)) NF=M
+C---CALCULATE THE FORM FACTOR
+ IF (NF.EQ.MAX(3,N)) THEN
+ SFNL=((BETAP(NF)+1/HWUALF(1,QKTHR))/
+ $ (BETAP(NF)+1/HWUALF(1,QLST)))**(1/BETA0(NF))
+ SLST=SFNL
+ ELSE
+ SFNL=((BETAP(NF)+1/HWUALF(1,RMASS(NF)))/
+ $ (BETAP(NF)+1/HWUALF(1,QLST)))**(1/BETA0(NF))
+ SLST=SFNL*SQRK(NF,N)
+ ENDIF
+ ENDIF
+ IF (RN.GT.1.E-3) THEN
+ QQBAR=QCDL3*(QLST/QCDL3)**(RN**BETAF)
+ ELSE
+ QQBAR=QCDL3
+ ENDIF
+ IF (SUDORD.NE.1) THEN
+C---FIND IN WHICH FLAVOUR INTERVAL THE SOLUTION LIES
+ IF (RN.GE.SFNL) THEN
+ NN=NF
+ ELSEIF (RN.GE.SLST) THEN
+ NN=MAX(3,N)
+ DO 210 M=MAX(3,N)+1,NF-1
+ 210 IF (RN.GE.SLST/SQRK(M,N)) NN=M
+ ELSE
+ NN=0
+ QQBAR=QCDL3
+ ENDIF
+ IF (NN.GT.0) THEN
+ IF (NN.EQ.NF) THEN
+ TARG=HWUALF(1,QLST)
+ ELSE
+ TARG=HWUALF(1,RMASS(NN+1))
+ RN=RN/SLST*SQRK(NN+1,N)
+ ENDIF
+ TARG=1/((BETAP(NN)+1/TARG)*RN**BETA0(NN)-BETAP(NN))
+C---NOW SOLVE HWUALF(1,QQBAR)=TARG FOR QQBAR ITERATIVELY
+ 7 QQBAR=MAX(QQBAR,HALF*QKTHR)
+ ALF=HWUALF(1,QQBAR)
+ IF (ABS(ALF-TARG).GT.ACCUR) THEN
+ NTRY=NTRY+1
+ IF (NTRY.GT.NBTRY) CALL HWWARN('HWBRAN',101,*999)
+ QQBAR=QQBAR*(1+3*PIFAC*(ALF-TARG)
+ $ /(BETA0(NN)*ALF**2*(1+BETAP(NN)*ALF)))
+ GOTO 7
+ ENDIF
+ ENDIF
+ ENDIF
+ IF (QQBAR.GT.QNOW.AND.QQBAR.GT.QKTHR) THEN
+ QNOW=QQBAR
+ ID2=N
+ ENDIF
+ ELSE
+ GOTO 9
+ ENDIF
+ 8 CONTINUE
+ ENDIF
+C--GLUON->DIQUARKS OPTION
+ 9 IF (QLST.LT.QDIQK) THEN
+ IF (PDIQK.NE.ZERO) THEN
+ RN=HWR()
+ DQQ=QLST*EXP(-RN/PDIQK)
+ IF (DQQ.GT.QNOW) THEN
+ IF (DQQ.GT.2.*RMASS(115)) THEN
+ QNOW=DQQ
+ ID2=115
+ ENDIF
+ ENDIF
+ ENDIF
+ ENDIF
+ ENDIF
+C--ENHANCE GLUON AND PHOTON EMISSION BY A FACTOR OF TWO IF THIS BRANCH
+C IS CAPABLE OF BEING THE HARDEST SO FAR
+ NREJ=1
+ IF (TMPAR(2).AND.0.25*MAX(QLST,QMAX).GT.HARDST) NREJ=2
+C--BRANCHING ID->ID+GLUON
+ QGTHR=HWBVMC(ID)+HWBVMC(13)
+ IF (QLST.GT.QGTHR) THEN
+ DO 300 IREJ=1,NREJ
+ RN=HWR()
+ SLST=HWUTAB(SUD(1,IS),QEV(1,IS),NQEV,QLST,INTER)
+ IF (RN.EQ.ZERO) THEN
+ SNOW=2.
+ ELSE
+ SNOW=SLST/RN
+ ENDIF
+ IF (SNOW.LT.ONE) THEN
+ QSUD=HWUTAB(QEV(1,IS),SUD(1,IS),NQEV,SNOW,INTER)
+C---IF FORM FACTOR DID NOT GET INVERTED CORRECTLY TRY LINEAR INSTEAD
+ IF (QSUD.GT.QLST) THEN
+ SNOW=HWUTAB(SUD(1,IS),QEV(1,IS),NQEV,QLST,1)/RN
+ QSUD=HWUTAB(QEV(1,IS),SUD(1,IS),NQEV,SNOW,1)
+ IF (QSUD.GT.QLST) THEN
+ CALL HWWARN('HWBRAN',1,*999)
+ QSUD=-1
+ ENDIF
+ ENDIF
+ IF (QSUD.GT.QGTHR.AND.QSUD.GT.QNOW) THEN
+ ID2=13
+ QNOW=QSUD
+ ENDIF
+ ENDIF
+ 300 CONTINUE
+ ENDIF
+C--BRANCHING ID->ID+PHOTON
+ IF (ICHRG(ID).NE.0) THEN
+ QGTHR=MAX(HWBVMC(ID)+HWBVMC(59),HWBVMC(59)*EXP(0.75))
+ IF (QMAX.GT.QGTHR) THEN
+ DO 400 IREJ=1,NREJ
+ RN=HWR()
+ IF (RN.EQ.ZERO) THEN
+ QGAM=0
+ ELSE
+ QGAM=(LOG(QMAX/HWBVMC(59))-0.75)**2
+ & +PIFAC*9/(ICHRG(ID)**2*ALPFAC*ALPHEM)*LOG(RN)
+ IF (QGAM.GT.ZERO) THEN
+ QGAM=HWBVMC(59)*EXP(0.75+SQRT(QGAM))
+ ELSE
+ QGAM=0
+ ENDIF
+ ENDIF
+ IF (QGAM.GT.QGTHR.AND.QGAM.GT.QNOW) THEN
+ ID2=59
+ QNOW=QGAM
+ ENDIF
+ 400 CONTINUE
+ ENDIF
+ ENDIF
+ IF (QNOW.GT.ZERO) THEN
+C--BRANCHING HAS OCCURRED
+ ZMIN=HWBVMC(ID2)/QNOW
+ ZMAX=1.-ZMIN
+ IF (ID.EQ.13) THEN
+ IF (ID2.EQ.13) THEN
+C--GLUON -> GLUON + GLUON
+ ID1=13
+ WMIN=ZMIN*ZMAX
+ ETEST=(1.-WMIN)**2*HWUALF(5-SUDORD*2,QNOW*WMIN)
+ ZRAT=(ZMAX*(1-ZMIN))/(ZMIN*(1-ZMAX))
+C--CHOOSE Z1 DISTRIBUTED ON (ZMIN,ZMAX)
+C ACCORDING TO GLUON BRANCHING FUNCTION
+ 10 Z1=ZMAX/(ZMAX+(1-ZMAX)*ZRAT**HWR())
+ Z2=1.-Z1
+ ZTEST=(1.-(Z1*Z2))**2*HWUALF(5-SUDORD*2,QNOW*(Z1*Z2))
+ IF (ZTEST.LT.ETEST*HWR()) GOTO 10
+ Z=Z1
+ ELSEIF (ID2.NE.115) THEN
+C--GLUON -> QUARKS
+ ID1=ID2+6
+ ETEST=ZMIN**2+ZMAX**2
+ 20 Z1=HWRUNI(0,ZMIN,ZMAX)
+ Z2=1.-Z1
+ ZTEST=Z1*Z1+Z2*Z2
+ IF (ZTEST.LT.ETEST*HWR()) GOTO 20
+ ELSE
+C--GLUON -> DIQUARKS
+ ID2=HWRINT(115,117)
+ ID1=ID2-6
+ Z1=HWRUNI(0,ZMIN,ZMAX)
+ Z2=1.-Z1
+ ENDIF
+ ELSE
+C--QUARK OR ANTIQUARK BRANCHING
+ IF (ID2.EQ.13) THEN
+C--TO GLUON
+ ZMAX=1.-HWBVMC(ID)/QNOW
+ WMIN=MIN(ZMIN*(1.-ZMIN),ZMAX*(1.-ZMAX))
+ ETEST=(1.+ZMAX**2)*HWUALF(5-SUDORD*2,QNOW*WMIN)
+ ZRAT=ZMAX/ZMIN
+ 30 Z1=ZMIN*ZRAT**HWR()
+ Z2=1.-Z1
+ ZTEST=(1.+Z2*Z2)*HWUALF(5-SUDORD*2,QNOW*Z1*Z2)
+ IF (ZTEST.LT.ETEST*HWR()) GOTO 30
+ ELSE
+C--TO PHOTON
+ ZMIN= HWBVMC(59)/QNOW
+ ZMAX=1-HWBVMC(ID)/QNOW
+ ZRAT=ZMAX/ZMIN
+ ETEST=1+(1-ZMIN)**2
+ 40 Z1=ZMIN*ZRAT**HWR()
+ Z2=1-Z1
+ ZTEST=1+Z2*Z2
+ IF (ZTEST.LT.ETEST*HWR()) GOTO 40
+ ENDIF
+C--QUARKS EMIT ON LOWER SIDE, ANTIQUARKS ON UPPER SIDE
+ Z=Z1
+ IF (JD.LE.6) THEN
+ Z1=Z2
+ Z2=1.-Z2
+ ID1=ID
+ ELSE
+ ID1=ID2
+ ID2=ID
+ ENDIF
+ ENDIF
+C--UPDATE THIS BRANCH AND CREATE NEW BRANCHES
+ XI=(QNOW/ENOW)**2
+ IF (ID1.NE.59.AND.ID2.NE.59) THEN
+ IF (ID.EQ.13.AND.ID1.NE.13) THEN
+ QLAM=QNOW
+ ELSE
+ QLAM=QNOW*Z1*Z2
+ ENDIF
+ IF (SUDORD.EQ.1.AND.HWUALF(2,QLAM).LT.HWR() .OR.
+ & (2.-XI)*(QNOW*Z1*Z2)**2.GT.EMSCA**2) THEN
+C--BRANCHING REJECTED: REDUCE Q AND REPEAT
+ QMAX=QNOW
+ QLST=QNOW
+ QNOW=-1.
+ GOTO 5
+ ENDIF
+ ENDIF
+C--IF THIS IS HARDEST EMISSION SO FAR, APPLY MATRIX-ELEMENT CORRECTION
+ IF (ID.NE.13.OR.ID1.EQ.13) THEN
+ QLAM=QNOW*Z1*Z2
+ REJFAC=1
+ IF (TMPAR(2).AND.QLAM.GT.HARDST) THEN
+C----SOFT MATRIX-ELEMENT CORRECTION TO TOP DECAYS
+ ITOP=JCOPAR(1,1)
+ IF (ISTHEP(ITOP).EQ.155.AND.(IDHW(ITOP).EQ.6
+ $ .OR.IDHW(ITOP).EQ.12)) THEN
+ AW=(PHEP(5,JDAHEP(1,ITOP))/PHEP(5,ITOP))**2
+ FF=0.5*(1-AW)*(1-2*AW+1/AW)
+ CC=0.25*(1-AW)**2
+ X1=1-2*CC*Z*(1-Z)*XI
+ X3=0.5*(1-AW+2*CC*Z*(1-Z)*XI-(1-2*Z)
+ & *HWUSQR(((1+AW-2*CC*Z*(1-Z)*XI)**2-4*AW)
+ & /(1-2*Z*(1-Z)*XI)))
+C-----JACOBIAN FACTOR
+ JJ=(1-X1)*(2-AW-X1-2*X3)*(1-2*Z*(1-Z)*XI)/(
+ $ 4*CC**2*((X1+AW)**2-4*AW)*Z**2*(1-Z)**2*(1-2*Z)*XI)
+C-----REJECTION FACTOR
+ XCUT=2*GCUTME/PHEP(5,ITOP)
+ IF (X3.GT.XCUT) REJFAC=FF*JJ
+ & *X3**2*(1-X1)*(1+(1-Z)**2)/(Z*XI)
+ & /((1+1/AW-2*AW)*((1-AW)*X3-(1-X1)
+ & *(1-X3)-X3**2)+(1+1/(2*AW))*X3*(X1+X3-1)**2
+ & +2*X3**2*(1-X1))
+ ELSEIF (MOD(ISTHEP(JCOPAR(1,1)),10).GE.3) THEN
+C---COLOUR PARTNER IS ALSO OUTGOING
+ X1=1-Z*(1-Z)*XI
+ X2=0.5*(1+Z*(1-Z)*XI +
+ $ (1-Z*(1-Z)*XI)*(1-2*Z)/SQRT(1-2*Z*(1-Z)*XI))
+ REJFAC=SQRT(2*X1-1)/(X1*Z*(1-Z))
+ $ *(1+(1-Z)**2)/(Z*XI)
+ $ *(1-X1)*(1-X2)/(X1**2+X2**2)
+C---CHECK WHETHER IT IS IN THE OVERLAP REGION
+ OTHXI=4*(1-X2)*X2**2/(X2**2-(2*X2-1)*(2*X1+X2-2)**2)
+ IF (OTHXI.LT.ONE) THEN
+ OTHZ=0.5*(1-SQRT(2*X2-1)/X2*(2*X1+X2-2))
+ REJFAC=REJFAC+SQRT(2*X2-1)/(X2*OTHZ*(1-OTHZ))
+ $ *(1+(1-OTHZ)**2)/(OTHZ*OTHXI)
+ $ *(1-X2)*(1-X1)/(X2**2+X1**2)
+ ENDIF
+ ELSE
+C---COLOUR PARTNER IS INCOMING (X1=XP, X2=ZP)
+ X1=1/(1+Z*(1-Z)*XI)
+ X2=0.5*(1+(1-2*Z)/SQRT(1-2*Z*(1-Z)*XI))
+ REJFAC=SQRT(3-2/X1)/(X1**2*Z*(1-Z))
+ $ *(1+(1-Z)**2)/(Z*XI)
+ $ *(1-X1)*(1-X2)/
+ $ (1+(1-X1-X2+2*X1*X2)**2+2*(1-X1)*(1-X2)*X1*X2)
+C---CHECK WHETHER IT IS IN THE OVERLAP REGION
+ OTHXI=(SQRT(X1+2*(1-X2)*(1-X2+X1*X2))-SQRT(X1))**2/
+ $ (1+X1-X2-SQRT(X1*(X1+2*(1-X2)*(1-X2+X1*X2))))
+ OTHZ=(SQRT(X1*(X1+2*(1-X2)*(1-X2+X1*X2)))-X1)/(1-X2)
+ IF (OTHXI.LT.OTHZ**2) THEN
+ REJFAC=REJFAC+OTHZ**3*(1-X1-X2+2*X1*X2)
+ $ /(X1**2*(1-OTHZ)*(OTHZ+OTHXI*(1-OTHZ)))
+ $ *(1+OTHZ**2)/((1-OTHZ)*OTHXI)
+ $ *(1-X1)*(1-X2)/
+ $ (1+(1-X1-X2+2*X1*X2)**2+2*(1-X1)*(1-X2)*X1*X2)
+ ENDIF
+ ENDIF
+ ENDIF
+ IF (NREJ*REJFAC*HWR().GT.ONE) THEN
+ QMAX=QNOW
+ QLST=QNOW
+ QNOW=-1.
+ GOTO 5
+ ENDIF
+ IF (QLAM.GT.HARDST) HARDST=QLAM
+ ENDIF
+ MPAR=NPAR+1
+ IDPAR(MPAR)=ID1
+ TMPAR(MPAR)=.TRUE.
+ PPAR(1,MPAR)=QNOW*Z1
+ PPAR(2,MPAR)=XI
+ PPAR(4,MPAR)=ENOW*Z1
+ NPAR=NPAR+2
+ IDPAR(NPAR)=ID2
+ TMPAR(NPAR)=.TRUE.
+ PPAR(1,NPAR)=QNOW*Z2
+ PPAR(2,NPAR)=XI
+ PPAR(4,NPAR)=ENOW*Z2
+C---NEW MOTHER-DAUGHTER RELATIONS
+ JDAPAR(1,KPAR)=MPAR
+ JDAPAR(2,KPAR)=NPAR
+ JMOPAR(1,MPAR)=KPAR
+ JMOPAR(1,NPAR)=KPAR
+C---NEW COLOUR CONNECTIONS
+ JCOPAR(3,KPAR)=NPAR
+ JCOPAR(4,KPAR)=MPAR
+ JCOPAR(1,MPAR)=NPAR
+ JCOPAR(2,MPAR)=KPAR
+ JCOPAR(1,NPAR)=KPAR
+ JCOPAR(2,NPAR)=MPAR
+C
+ ENDIF
+ ENDIF
+ IF (QNOW.LT.ZERO) THEN
+C--BRANCHING STOPS
+ IF (ID.EQ.IDPAR(2).AND.PPAR(5,2).GT.1D-6) THEN
+ PPAR(5,KPAR)=PPAR(5,2)**2
+ ELSE
+ PPAR(5,KPAR)=RMASS(ID)**2
+ ENDIF
+ PMOM=PPAR(4,KPAR)**2-PPAR(5,KPAR)
+ IF (PMOM.LT.-1E-6) CALL HWWARN('HWBRAN',104,*999)
+ IF (PMOM.LT.ZERO) PMOM=ZERO
+ PPAR(3,KPAR)=SQRT(PMOM)
+ JDAPAR(1,KPAR)=0
+ JDAPAR(2,KPAR)=0
+ JCOPAR(3,KPAR)=0
+ JCOPAR(4,KPAR)=0
+ ENDIF
+ 999 END
+CDECK ID>, HWBRCN.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBRCN
+C-----------------------------------------------------------------------
+C SUBROUTINE TO REPLACE HWBCON IN RPARITY VIOLATING SUSY
+C BASED ON HWBCON BY BRW
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER IHEP,IST,ID,JC,JD,JHEP,IDP,IDM,IDP2,IDM2,
+ & RHEP,IST2,ORG,ANTC,XHEP,IP,COLP
+ LOGICAL BVVUSE,BVVHRD,BVDEC1,BVDEC2,COLRD,ACOLRD,BVHRD,BVHRD2,
+ & BVDEC3
+C--logical functions to decide if baryon number violating
+C--BVDEC1 DELTAB=+1
+ BVDEC1(IP) = ((IDHW(IP).GE.419.AND.IDHW(IP).LE.424).OR.
+ & IDHW(IP).EQ.411.OR.IDHW(IP).EQ.412.OR.
+ & IDHW(IP).EQ.449).AND.IDHW(JDAHEP(1,IP)).LE.6.
+ & AND.IDHW(JDAHEP(1,IP)+1).LE.6.AND.
+ & IDHW(JDAHEP(2,IP)).LE.6
+C--BVDEC2 DELTAB=-1
+ BVDEC2(IP) = ((IDHW(IP).GE.413.AND.IDHW(IP).LE.418).OR.
+ & IDHW(IP).EQ.405.OR.IDHW(IP).EQ.406.OR.
+ & IDHW(IP).EQ.449).AND.
+ & IDHW(JDAHEP(1,IP)).GE.7.AND.IDHW(JDAHEP(1,IP)).LE.12.AND.
+ & IDHW(JDAHEP(1,IP)+1).GE.7.AND.IDHW(JDAHEP(1,IP)+1).LE.12.AND.
+ & IDHW(JDAHEP(2,IP)).GE.7.AND.IDHW(JDAHEP(2,IP)).LE.12
+C--Neutralino and Chargino Decays
+ BVDEC3(IP) = ((IDHW(IP).GE.450.AND.IDHW(IP).LE.457).AND.
+ & (IDHW(JDAHEP(1,IP)).LE.12.AND.IDHW(JDAHEP(1,IP)+1).LE.12.
+ & .AND.IDHW(JDAHEP(2,IP)).LE.12))
+C--Now the hard vertices
+ BVHRD(IP) = IDHW(IP).EQ.15.AND.IDHW(JMOHEP(1,IP)).LE.12.
+ & AND.IDHW(JMOHEP(2,IP)).LE.12.AND.IDHW(JDAHEP(1,IP)).LE.12.
+ & AND.IDHW(JDAHEP(2,IP)).GE.449.AND.IDHW(JDAHEP(2,IP)).LE.457
+ BVHRD2(IP) = IDHW(IP).EQ.15.AND.IDHW(JMOHEP(1,IP)).LE.12.
+ & AND.IDHW(JMOHEP(2,IP)).LE.12.AND.IDHW(JDAHEP(1,IP)).GE.198.
+ & AND.IDHW(JDAHEP(1,IP)).LE.207.
+ & AND.ABS(IDHEP(JDAHEP(2,IP))).GT.1000000
+C--Those particles which are coloured
+ COLRD(IP) = IP.LE.6.OR.IP.EQ.13.OR.IP.EQ.449.OR.
+ & (IP.GE.401.AND.IP.LE.406).OR.(IP.GE.413.AND.IP.LE.418).OR.
+ & (IP.GE.115.AND.IP.LE.120).OR.IP.EQ.59
+C--Those particles which are anticoloured
+ ACOLRD(IP) = (IP.GE.7.AND.IP.LE.12).OR.IP.EQ.13.OR.IP.EQ.449.OR.
+ & (IP.GE.407.AND.IP.LE.412).OR.(IP.GE.419.AND.IP.LE.424).OR.
+ & (IP.GE.109.AND.IP.LE.114).OR.IP.EQ.59
+ IF (IERROR.NE.0) RETURN
+ COLP = 0
+ IF(COLUPD.AND.HRDCOL(1,3).NE.0) THEN
+ JD = 0
+ DO IHEP = HRDCOL(1,3),HRDCOL(1,3)+4
+ JD = JD+1
+ IF(JD.NE.3) THEN
+ JMOHEP(2,IHEP) = HRDCOL(1,JD)
+ JDAHEP(2,IHEP) = HRDCOL(2,JD)
+ ENDIF
+ ENDDO
+ COLUPD=.FALSE.
+ DO IHEP=1,5
+ DO JHEP=1,2
+ HRDCOL(JHEP,IHEP)=0
+ ENDDO
+ ENDDO
+ ELSEIF(COLUPD) THEN
+ RETURN
+ ENDIF
+ DO 110 IHEP=1,NHEP
+ IST=ISTHEP(IHEP)
+ JD =0
+ BVVUSE = .FALSE.
+ BVVHRD = .FALSE.
+C---LOOK FOR PARTONS WITHOUT COLOUR MOTHERS
+ IF ((IST.LT.145.OR.IST.GT.152).AND.IST.NE.155) GOTO 110
+ IF (JMOHEP(2,IHEP).EQ.0) THEN
+C---FIND COLOUR-CONNECTED PARTON
+ IF(IST.EQ.155.AND.ABS(IDHEP(IHEP)).EQ.6) THEN
+ JC = JMOHEP(1,IHEP)
+ ELSEIF(IST.EQ.155) THEN
+ GOTO 110
+ ELSE
+ JC=JMOHEP(1,IHEP)
+ ENDIF
+ IF (IST.NE.152) JC=JMOHEP(1,JC)
+C--Correction for BV
+ IF(HRDCOL(1,1).NE.0) THEN
+ IDP = IDHW(HRDCOL(1,1))
+ IDP2 = 0
+ ELSE
+ IDP = 0
+ IDP2 = 0
+ ENDIF
+ IDM = JMOHEP(1,JC)
+ IF(BVDEC1(IDM).OR.BVDEC2(IDM)) THEN
+ IF(IDHW(IDM).EQ.449.AND.JDAHEP(1,IDM).EQ.JC) THEN
+ JC=JMOHEP(2,JC)
+ ELSE
+ JD = JMOHEP(2,JC)
+ JC = IDM
+ IF(JC.EQ.JD) JD= JDAHEP(2,JC-1)
+ BVVUSE = .TRUE.
+ ENDIF
+C--NEW FOR BV HARD PROCESS
+ ELSEIF(BVHRD(IDM)) THEN
+ IF(IDHW(JDAHEP(2,JMOHEP(1,JC))).EQ.449) THEN
+ JD = JMOHEP(2,JC)
+ IDM2 = JDAHEP(2,HRDCOL(1,2))
+ IF(JD.EQ.IDM2) JD = HRDCOL(1,1)
+ IF(JC.EQ.JDAHEP(2,IDM2).AND.COLRD(IDHW(IHEP))) THEN
+ JC = JMOHEP(2,JC)
+ ELSEIF(JC.EQ.IDM2) THEN
+ IF(JDAHEP(2,JMOHEP(2,JC)).EQ.JC) THEN
+ JC = JMOHEP(2,JC)
+ ELSE
+ JMOHEP(2,IHEP)=JMOHEP(2,JC)
+ GOTO 110
+ ENDIF
+ ELSE
+ JC = HRDCOL(1,1)
+ BVVUSE = .TRUE.
+ BVVHRD = .TRUE.
+ IF(ACOLRD(IDHW(IHEP))) JC = JD
+ IF(JC.EQ.IDM2) GOTO 110
+ ENDIF
+ ELSE
+ JC =JMOHEP(2,JC)
+ BVVUSE = .TRUE.
+ BVVHRD = .TRUE.
+ ENDIF
+ ELSEIF(BVHRD2(IDM)) THEN
+ JD = JMOHEP(2,JC)
+ IF(JC.EQ.JDAHEP(2,HRDCOL(1,2))) THEN
+ JMOHEP(2,IHEP)=JMOHEP(2,JC)
+ GOTO 110
+ ENDIF
+ IF(JD.EQ.JDAHEP(2,HRDCOL(1,2))) JD = HRDCOL(1,1)
+ BVVUSE=.TRUE.
+ BVVHRD = .TRUE.
+ IF(JC.EQ.JDAHEP(2,HRDCOL(1,2))) THEN
+ JC = JMOHEP(2,JC)
+ ELSE
+ JC = HRDCOL(1,1)
+ ENDIF
+ ELSE
+ JC =JMOHEP(2,JC)
+ ENDIF
+ IF (JC.EQ.0) CALL HWWARN('HWBCON',51,*110)
+C---FIND SPECTATOR WHEN JC IS DECAYED HEAVY QUARK OR SUSY PARTICLE
+ IF (ISTHEP(JC).EQ.155) THEN
+ IF (IDHEP(JMOHEP(1,JC)).EQ.94) THEN
+C---DECAYED BEFORE HADRONIZING
+ IF(BVVHRD) THEN
+ JHEP = JC
+ ELSEIF(BVVUSE) THEN
+ JHEP=JDAHEP(2,JC-1)
+ ELSE
+ JHEP=JMOHEP(2,JC)
+ ENDIF
+ IF(JHEP.EQ.0.AND.ABS(IDHEP(JC)).EQ.6) THEN
+ JHEP = JMOHEP(1,JMOHEP(1,JC))
+ IF(BVDEC1(JMOHEP(1,JHEP)).OR.BVDEC2(JMOHEP(1,JHEP))) THEN
+ JC = JHEP
+ JHEP = JDAHEP(2,JC-1)
+ ELSE
+ JHEP = 0
+ ENDIF
+ ENDIF
+ IF(BVVUSE.AND.ABS(IDHEP(JHEP)).GT.1000000.AND.
+ & ISTHEP(JHEP).NE.155.OR.JHEP.EQ.0) GOTO 110
+ ID=IDHW(JHEP)
+ IF (ISTHEP(JHEP).EQ.155) THEN
+C---SPECIAL FOR GLUINO DECAYS
+ IF (ID.EQ.449) THEN
+ ID=IDHW(JC)
+ IF(BVVUSE) THEN
+ ID=IDHW(IHEP)
+ IF(ID.LE.6.OR.ID.EQ.13.OR.
+ & (ID.GE.115.AND.ID.LE.120)) THEN
+ ID = 7
+ ELSE
+ ID = 1
+ ENDIF
+ ENDIF
+ CALL HWBRC1(JC,ID,JHEP,.TRUE.,*999)
+ IF(BVVUSE.AND.JMOHEP(1,JC).EQ.JMOHEP(1,JD)) JC =JD
+ ELSE
+ JC=JDAHEP(2,JHEP)
+ IF(COLRD(IDHW(IHEP)).AND.IDHW(JDAHEP(1,JHEP)).EQ.449)
+ & JC=JDAHEP(1,JHEP)
+ IF(BVVUSE.AND.JMOHEP(1,JC).EQ.JMOHEP(1,JD)) JC =JD
+ ENDIF
+ ELSE
+ IF(BVVUSE) THEN
+ IF(BVDEC2(JMOHEP(1,JHEP)).OR.JD.NE.JHEP.OR.
+ & BVHRD(JMOHEP(1,JHEP)).OR.BVHRD2(JMOHEP(1,JHEP))) THEN
+ JC = JD
+ GOTO 100
+ ELSE
+ JMOHEP(2,IHEP)=JHEP
+ ID = IDHW(JHEP)
+ IF((ID.GE.7.AND.ID.LE.12).OR.
+ & (ID.GE.109.AND.ID.LE.114)) JMOHEP(2,JHEP)=IHEP
+ ENDIF
+ ELSE
+C--new for particles connected to BV
+ IDM = JMOHEP(1,JHEP)
+ IF(BVDEC1(IDM).OR.BVHRD(IDM).OR.BVHRD2(IDM)) THEN
+ JC = JHEP
+ IF(ABS(IDHEP(IHEP)).LT.1000000) GOTO 100
+ JMOHEP(2,IHEP)=JHEP
+ GOTO 110
+ ENDIF
+C--new for top's from BV
+ ID = IDHW(JC)
+ IDP = JMOHEP(1,JMOHEP(1,JMOHEP(1,JC)))
+ IF((ID.EQ.6.AND.(BVDEC1(IDP))).
+ & OR.(ID.EQ.12.AND.BVDEC2(IDP)).
+ & OR.((ID.EQ.12.OR.ID.EQ.449).AND.BVHRD(IDP))) THEN
+ JMOHEP(2,IHEP)=JHEP
+ IF(JDAHEP(2,JHEP).EQ.JC) JDAHEP(2,JHEP)=IHEP
+ ELSE
+ IF((IDHW(IHEP).GE.7.AND.IDHW(IHEP).LE.12.
+ & AND.IDHW(JHEP).GE.7.AND.IDHW(JHEP).LE.12).OR.
+ & (IDHW(IHEP).LE.6.AND.IDHW(JHEP).LE.6)) THEN
+ JMOHEP(2,IHEP)=JHEP
+ ELSE
+ JMOHEP(2,IHEP)=JHEP
+ IF((COLRD(IDHW(IHEP)).AND.ACOLRD(IDHW(JHEP))).OR.
+ & (.NOT.COLRD(IDHW(IHEP)).AND.
+ & .NOT.ACOLRD(IDHW(JHEP)))) THEN
+ IF(JDAHEP(2,JHEP).EQ.0) THEN
+ JDAHEP(2,JHEP)=IHEP
+ ELSEIF(JMOHEP(2,JDAHEP(2,JHEP)).NE.JHEP) THEN
+ JDAHEP(2,JHEP)=IHEP
+ ENDIF
+ ELSE
+ IF(JMOHEP(2,JHEP).EQ.JC) JMOHEP(2,JHEP)=IHEP
+ ENDIF
+ ENDIF
+ ENDIF
+ ENDIF
+ GOTO 110
+ ENDIF
+ ELSE
+ JC=JMOHEP(2,JC)
+ ENDIF
+ ENDIF
+ 100 CONTINUE
+ IF(BVVUSE.AND.ABS(IDHEP(JC)).LT.1000000.AND.JC.NE.JD
+ & .AND.JD.NE.0.AND.JD.NE.JMOHEP(1,JC)) JC = JD
+ IF(BVVUSE.AND.ABS(IDHEP(JC)).GT.1000000) THEN
+ IF(COLRD(IDHW(IHEP)).AND..NOT.BVVHRD) GOTO 110
+ ENDIF
+ IF(BVVUSE.AND.ISTHEP(JC).EQ.149) JC=JMOHEP(1,JMOHEP(1,JC))
+C--SEARCH IN THE JET
+ IF((ISTHEP(JC).GT.145.AND.ISTHEP(JC).LT.152).AND.
+ & ISTHEP(IHEP).EQ.155) THEN
+ JMOHEP(2,IHEP) = JC
+ GOTO 110
+ ENDIF
+ CALL HWBRC2(COLP,IHEP,JC,.TRUE.,BVVUSE,BVVHRD)
+ IF(COLP.NE.0) THEN
+ JMOHEP(2,IHEP) = COLP
+ IF(COLRD(IDHW(IHEP)).AND.ACOLRD(IDHW(COLP)).
+ & AND.JDAHEP(2,COLP).EQ.0)
+ & JDAHEP(2,COLP) = IHEP
+ IF((IDHW(IHEP).GE.7.AND.IDHW(IHEP).LE.12).AND.
+ & (IDHW(COLP).GE.7.AND.IDHW(COLP).LE.12)) THEN
+ IF(JMOHEP(2,COLP).EQ.0) JMOHEP(2,COLP) = IHEP
+ ENDIF
+ ENDIF
+ ENDIF
+ 110 CONTINUE
+C---BREAK COLOUR CONNECTIONS WITH PHOTONS modified for Rslash
+ IHEP=1
+ 130 IF (IHEP.LE.NHEP) THEN
+ IF (IDHW(IHEP).EQ.59 .AND. ISTHEP(IHEP).EQ.149.AND.
+ & (JMOHEP(2,IHEP).NE.IHEP.OR.JDAHEP(2,IHEP).NE.IHEP)) THEN
+ IF(JMOHEP(2,IHEP).NE.0) THEN
+ IF (JDAHEP(2,JMOHEP(2,IHEP)).EQ.IHEP)
+ & JDAHEP(2,JMOHEP(2,IHEP))=JDAHEP(2,IHEP)
+ ENDIF
+ IF (JDAHEP(2,IHEP).NE.0) THEN
+ IF (JMOHEP(2,JDAHEP(2,IHEP)).EQ.IHEP)
+ & JMOHEP(2,JDAHEP(2,IHEP))=JMOHEP(2,IHEP)
+ ENDIF
+ DO RHEP=1,NHEP
+ IST=ISTHEP(RHEP)
+ IF((IST.GE.147.AND.IST.LE.149).AND.JDAHEP(2,RHEP).EQ.IHEP)
+ & JDAHEP(2,RHEP)=JMOHEP(2,IHEP)
+ ENDDO
+ DO RHEP=1,NHEP
+ IST=ISTHEP(RHEP)
+ IF((IST.GE.147.AND.IST.LE.149).AND.JMOHEP(2,RHEP).EQ.IHEP)
+ & JMOHEP(2,RHEP) = JDAHEP(2,IHEP)
+ ENDDO
+ JMOHEP(2,IHEP)=IHEP
+ JDAHEP(2,IHEP)=IHEP
+ ENDIF
+ IHEP=IHEP+1
+ GOTO 130
+ ENDIF
+C--Update the BV anticolour corrections
+ DO 210 IHEP=1,NHEP+1
+ IF(IHEP.EQ.1) GOTO 210
+ IST2 = 0
+ IF(IHEP.EQ.NHEP+1) THEN
+ ANTC = HRDCOL(1,1)
+ IF(ANTC.EQ.0.OR.(IDHW(JMOHEP(1,HRDCOL(1,2))).LE.6)) GOTO 210
+ IST=155
+ XHEP=HRDCOL(1,2)
+ IF(ANTC.EQ.JDAHEP(2,XHEP)) ANTC=JDAHEP(1,JDAHEP(1,ANTC))
+ IF(ANTC.NE.0.AND.JDAHEP(1,ANTC).NE.0) IST2=ISTHEP(ANTC)
+ ELSE
+ ANTC = JDAHEP(2,IHEP-1)
+ IF(ANTC.NE.0) IST2=ISTHEP(ANTC)
+ IST=ISTHEP(IHEP)
+ IDM = IDHW(IHEP)
+ XHEP=IHEP
+ ENDIF
+ JC = 0
+ JHEP = 0
+ JD = 0
+ ORG = 0
+ IF(IST.EQ.155.AND.IST2.EQ.155) THEN
+ IDM = IDHW(XHEP)
+ ORG = ANTC
+ IF(BVDEC1(XHEP).OR.BVDEC2(XHEP).OR.BVHRD(XHEP).OR.
+ & BVHRD2(XHEP)) THEN
+ JC=ANTC
+ ID = IDHW(JC)
+ JHEP = JC
+ IF(BVDEC1(JC).OR.BVDEC2(JC)) THEN
+ IF(IHEP.EQ.(NHEP+1)) ANTC=JDAHEP(1,JC)
+ GOTO 200
+ ENDIF
+ IF (ID.EQ.449) THEN
+C--SPECIAL FOR GLUINO DECAYS
+ ID=IDHW(XHEP)
+ IF(IHEP.EQ.NHEP+1) ID = 407
+ CALL HWBRC1(JC,ID,JHEP,.FALSE.,*999)
+ ELSE
+ IF(IDHW(JDAHEP(1,JHEP)).EQ.449) THEN
+ JC=JDAHEP(1,JHEP)
+ ELSE
+ JC=JDAHEP(2,JHEP)
+ ENDIF
+ ENDIF
+C--SEARCH IN JET
+ CALL HWBRC2(COLP,XHEP,JC,.FALSE.,BVVUSE,.FALSE.)
+ ANTC = COLP
+ IF(IHEP.LE.NHEP.AND.ACOLRD(IDHW(IHEP)).AND.
+ & COLRD(IDHW(COLP)).AND.JMOHEP(2,COLP).EQ.0) THEN
+ JMOHEP(2,COLP) = IHEP
+ ELSEIF(IHEP.LE.NHEP.AND.IDHW(IHEP).LE.6.AND.
+ & IDHW(COLP).LE.6.AND.JDAHEP(2,COLP).EQ.0) THEN
+ JDAHEP(2,COLP) = IHEP
+ ELSEIF(IHEP.GT.NHEP.AND.
+ & ((BVHRD(XHEP).AND.COLRD(JDAHEP(1,XHEP))).
+ & OR.(BVHRD2(XHEP).AND.ACOLRD(JDAHEP(2,XHEP)))).AND.
+ & ACOLRD(IDHW(COLP)).AND.JDAHEP(2,COLP).EQ.0) THEN
+ JDAHEP(2,COLP) = IHEP
+ ENDIF
+ ENDIF
+ ENDIF
+ 200 CONTINUE
+ IF(IHEP.EQ.NHEP+1) THEN
+ IF(HRDCOL(1,1).NE.ANTC.AND.ANTC.NE.0) THEN
+ HRDCOL(1,1)=ANTC
+ IF(JDAHEP(2,ANTC).EQ.IHEP) THEN
+ IF(JDAHEP(2,JMOHEP(1,HRDCOL(1,2))).EQ.JDAHEP(2,HRDCOL(1,2)).
+ & AND.JMOHEP(2,JDAHEP(2,HRDCOL(1,2))).EQ.JMOHEP(1,HRDCOL(1,2)))
+ & THEN
+ JDAHEP(2,ANTC) = JMOHEP(2,HRDCOL(1,2))
+ ELSE
+ JDAHEP(2,ANTC) = JMOHEP(1,HRDCOL(1,2))
+ ENDIF
+ ELSEIF(JMOHEP(2,ANTC).EQ.IHEP) THEN
+ JMOHEP(2,ANTC) = JMOHEP(1,HRDCOL(1,2))
+ ENDIF
+ ENDIF
+ ELSEIF(IHEP.NE.1) THEN
+ IF(JDAHEP(2,IHEP-1).NE.ANTC.AND.ANTC.NE.0) JDAHEP(2,IHEP-1)=ANTC
+ ENDIF
+ 210 CONTINUE
+C--Update BV decaying particles connections
+ DO 310 IHEP=1,NHEP+1
+ IF(IHEP.EQ.1) GOTO 310
+ IF(IHEP.EQ.NHEP+1) THEN
+ ANTC=HRDCOL(1,1)
+ IF(ANTC.EQ.0.OR.IDHW(JDAHEP(1,HRDCOL(1,2))).LE.6) GOTO 310
+ IST=155
+ XHEP=HRDCOL(1,2)
+ IF(ANTC.EQ.JDAHEP(2,XHEP)) ANTC=JDAHEP(1,JDAHEP(1,ANTC))
+ ELSE
+ ANTC=JMOHEP(2,IHEP)
+ IST=ISTHEP(IHEP)
+ IDM = IDHW(IHEP)
+ XHEP=IHEP
+ ENDIF
+ IST2 = 0
+ JC = 0
+ JD = 0
+ IF(ANTC.NE.0.AND.IHEP.NE.NHEP+1) THEN
+ IF(JDAHEP(1,ANTC).NE.0) IST2 = ISTHEP(ANTC)
+ ELSEIF(ANTC.NE.0.AND.IHEP.EQ.NHEP+1) THEN
+ IST2=ISTHEP(ANTC)
+ ENDIF
+ IF(IST.EQ.155.AND.IST2.EQ.155) THEN
+ IF(BVDEC2(XHEP).OR.BVHRD(XHEP).OR.BVHRD2(XHEP)) THEN
+C--FIND COLOUR CONNECTED PARTON
+ JC = ANTC
+ ID=IDHW(JC)
+ JHEP = JC
+ IF(BVDEC2(JHEP)) THEN
+ ANTC=JC
+ GOTO 300
+ ENDIF
+ IF (ID.EQ.449) THEN
+ ID=IDHW(XHEP)
+ IF(IHEP.EQ.NHEP+1) ID = 401
+C--SPECIAL FOR GLUINO DECAYS
+ CALL HWBRC1(JC,ID,JHEP,.TRUE.,*999)
+ ELSE
+ IF(IDHW(JDAHEP(1,JHEP)).EQ.449) THEN
+ JC=JDAHEP(1,JHEP)
+ ELSE
+ JC=JDAHEP(2,JHEP)
+ ENDIF
+ ENDIF
+C--SEARCH IN JET
+ CALL HWBRC2(COLP,XHEP,JC,.TRUE.,BVVUSE,.FALSE.)
+ ANTC = COLP
+ IF(COLP.EQ.0) GOTO 300
+ IF(IHEP.LE.NHEP) THEN
+ IF(JDAHEP(2,COLP).EQ.0) THEN
+ JDAHEP(2,COLP) = JDAHEP(2,IHEP)
+ ELSEIF(JMOHEP(2,JDAHEP(2,COLP)).NE.COLP) THEN
+ JDAHEP(2,COLP) = JDAHEP(2,IHEP)
+ ENDIF
+ ELSEIF(IHEP.GT.NHEP.AND.
+ & ((BVHRD(XHEP).AND.ACOLRD(JDAHEP(1,XHEP)).AND.
+ & IDHW(JDAHEP(2,XHEP)).EQ.449).
+ & OR.(BVHRD2(XHEP).AND.ACOLRD(JDAHEP(2,XHEP)))).AND.
+ & ACOLRD(IDHW(COLP)).AND.JDAHEP(2,COLP).EQ.0) THEN
+ JDAHEP(2,COLP) = IHEP
+ ENDIF
+ ENDIF
+ ENDIF
+ 300 CONTINUE
+ IF(IHEP.NE.NHEP+1.AND.IHEP.NE.1) THEN
+ IF(JMOHEP(2,IHEP).NE.ANTC.AND.ANTC.NE.0) JMOHEP(2,IHEP)=ANTC
+ ELSEIF(IHEP.GT.NHEP) THEN
+ IF(HRDCOL(1,1).NE.ANTC.AND.ANTC.NE.0) HRDCOL(1,1)=ANTC
+ IF(ANTC.EQ.0) GOTO 310
+ IF(JDAHEP(2,ANTC).EQ.IHEP) THEN
+ IF(JDAHEP(2,JMOHEP(1,HRDCOL(1,2))).EQ.JDAHEP(2,HRDCOL(1,2)).
+ & AND.JMOHEP(2,JDAHEP(2,HRDCOL(1,2))).EQ.JMOHEP(1,HRDCOL(1,2)))
+ & THEN
+ JDAHEP(2,ANTC) = JMOHEP(2,HRDCOL(1,2))
+ ELSE
+ JDAHEP(2,ANTC) = JMOHEP(1,HRDCOL(1,2))
+ ENDIF
+ ELSEIF(JMOHEP(2,ANTC).EQ.IHEP) THEN
+ JMOHEP(2,ANTC) = JMOHEP(1,HRDCOL(1,2))
+ ENDIF
+ ENDIF
+ 310 CONTINUE
+C--Update partons connected to decaying SUSY particle
+ DO 400 IHEP=1,NHEP
+ IST=ISTHEP(IHEP)
+C--LOOK FOR PARTONS CONNECTED TO A DECAYING SUSY PARTICLE
+ IF (IST.LT.145.OR.IST.GT.152) GOTO 400
+ IF(JMOHEP(2,IHEP).EQ.0) GOTO 400
+ IF(ISTHEP(JMOHEP(2,IHEP)).EQ.155) THEN
+C--FIND THE COLOUR CONNECTED PARTON
+ JC=JMOHEP(2,IHEP)
+ ID=IDHW(JC)
+ JHEP = JC
+ IF(BVDEC2(JC).AND.IDHW(JC).NE.449) GOTO 400
+ IF (ID.EQ.449) THEN
+C--SPECIAL FOR GLUINO DECAYS
+ ID=IDHW(IHEP)
+ CALL HWBRC1(JC,ID,JHEP,.TRUE.,*999)
+ ELSE
+ ID=IDHW(IHEP)
+ IF(COLRD(ID).AND.IDHW(JDAHEP(1,JC)).EQ.449) THEN
+ JC=JDAHEP(1,JHEP)
+ ELSE
+ JC=JDAHEP(2,JHEP)
+ ENDIF
+ ENDIF
+C--SEARCH IN JET
+ CALL HWBRC2(COLP,IHEP,JC,.TRUE.,BVVUSE,.FALSE.)
+ JMOHEP(2,IHEP) = COLP
+ ENDIF
+ 400 CONTINUE
+C--Update partons connected to decaying SUSY particle
+ DO 500 IHEP=1,NHEP
+ IST=ISTHEP(IHEP)
+C--LOOK FOR PARTONS CONNECTED TO A DECAYING SUSY PARTICLE
+ IF (IST.LT.145.OR.IST.GT.152) GOTO 500
+ IF(JDAHEP(2,IHEP).EQ.0) GOTO 500
+ IF(ISTHEP(JDAHEP(2,IHEP)).EQ.155) THEN
+C--FIND THE COLOUR CONNECTED PARTON
+ JC=JDAHEP(2,IHEP)
+ ID=IDHW(JC)
+ ID=IDHW(JC)
+ IF (ID.EQ.449) THEN
+ ID=IDHW(IHEP)
+C--SPECIAL FOR GLUINO DECAYS
+ JHEP = JC
+ CALL HWBRC1(JC,ID,JHEP,.FALSE.,*999)
+ ELSE
+ IF(ACOLRD(IDHW(IHEP)).AND.IDHW(JDAHEP(1,JC)).EQ.449) THEN
+ JC = JDAHEP(1,JC)
+ ELSE
+ JC=JDAHEP(2,JC)
+ ENDIF
+ ENDIF
+C--SEARCH IN THE JET
+ CALL HWBRC2(COLP,IHEP,JC,.FALSE.,BVVUSE,.FALSE.)
+ IF(COLP.NE.0) JDAHEP(2,IHEP) = COLP
+ ENDIF
+ 500 CONTINUE
+C--Flavour and anticolour connections in Rslash
+ DO 610 IHEP=1,NHEP
+ IST=ISTHEP(IHEP)
+ IF(IST.LT.145.OR.IST.GT.152.OR.JDAHEP(2,IHEP).NE.0) GOTO 610
+ JD = 0
+ BVVUSE = .FALSE.
+ JC = JMOHEP(1,IHEP)
+ IF(IST.NE.152) JC = JMOHEP(1,JC)
+ IF(JC.EQ.0) CALL HWWARN('HWBRCN',51,*610)
+C--For particles which came from a top decay
+ IF(ABS(IDHEP(JMOHEP(1,JC))).EQ.6) THEN
+ JD = JMOHEP(1,JMOHEP(1,JMOHEP(1,JC)))
+C--flavour connect to self if needed
+ IF(JDAHEP(2,JMOHEP(1,JC)-1).EQ.JMOHEP(1,JC)) THEN
+ JDAHEP(2,IHEP) = IHEP
+ GOTO 610
+ ELSEIF(JDAHEP(2,JMOHEP(1,JC)-1).NE.0) THEN
+ JDAHEP(2,IHEP) = JDAHEP(2,JMOHEP(1,JC)-1)
+ GOTO 610
+ ELSE
+ JC = JD
+ ENDIF
+ ENDIF
+C--Decide if this came from a BV decay
+ IDM = JMOHEP(1,JC)
+ IF(BVDEC1(IDM).OR.BVDEC2(IDM).OR.BVDEC3(IDM).
+ & OR.BVHRD(IDM).OR.BVHRD2(IDM)) THEN
+C--Do BV piece
+ IF(JDAHEP(2,JC).EQ.JMOHEP(1,JC)) THEN
+ IF(IDHW(JMOHEP(1,JC)).EQ.449.AND.
+ & JDAHEP(1,JMOHEP(1,JC)).EQ.JC) THEN
+ JC = JDAHEP(2,JMOHEP(1,JC)-1)
+ ELSE
+ JC = JMOHEP(2,JMOHEP(1,JC))
+ ENDIF
+ IF(ABS(IDHEP(JC)).LT.1000000) THEN
+ IF(JDAHEP(1,JC).EQ.0) THEN
+ JDAHEP(2,IHEP) = JC
+ GOTO 610
+ ELSE
+ GOTO 600
+ ENDIF
+ ELSEIF(ABS(IDHEP(JC)).GT.1000000
+ & .AND.ISTHEP(JC).NE.155) THEN
+ GOTO 610
+ ENDIF
+ IF(ISTHEP(JC).EQ.155.AND.ACOLRD(IDHW(IHEP))) THEN
+ JC = JDAHEP(1,JC)
+ ELSE
+ IF(ISTHEP(JC).EQ.155.AND.IDHW(JDAHEP(1,JC)).NE.449) THEN
+ JC = JDAHEP(1,JC)
+ ELSE
+ JC = JDAHEP(2,JC)
+ ENDIF
+ ENDIF
+ ELSE
+C--For the hard process
+ IF(IDHW(IDM).EQ.15.AND.JC.EQ.JDAHEP(2,JMOHEP(1,JC))) THEN
+ JDAHEP(2,IHEP) = JDAHEP(2,JC)
+ GOTO 610
+ ELSEIF(IDHW(IDM).EQ.15.AND.IDHW(IHEP).NE.449) THEN
+ JD=HRDCOL(1,1)
+ IF(BVHRD(IDM).AND.IDHW(JDAHEP(2,IDM)).NE.449) THEN
+ JC = JDAHEP(2,JC)
+ GOTO 600
+ ELSEIF(JMOHEP(1,JDAHEP(2,JC)).EQ.JD) THEN
+ JC=JDAHEP(2,JC)
+ GOTO 600
+ ENDIF
+ IF(JDAHEP(2,JC).EQ.8) JC = JD
+ ELSE
+ JD=JMOHEP(2,JMOHEP(1,JC))
+ ENDIF
+ IF(COLRD(IDHW(IHEP)).AND..NOT.ACOLRD(IDHW(IHEP)).AND.
+ & ABS(IDHEP(JD)).GT.1000000.AND.ISTHEP(JD).NE.155) THEN
+ JDAHEP(2,IHEP) = JD
+ IF(JDAHEP(2,JD).EQ.0) JDAHEP(2,JD) = IHEP
+ ENDIF
+ IF(ABS(IDHEP(JD)).GT.1000000
+ & .AND.ISTHEP(JD).NE.155) GOTO 610
+ IF(ISTHEP(JC).EQ.149) THEN
+ JDAHEP(2,IHEP)=JC
+ GOTO 610
+ ENDIF
+ IF(ACOLRD(IDHW(IHEP)).AND.IDHW(JC).EQ.449.AND.BVDEC2(JC)) THEN
+ JC = JDAHEP(1,JC)
+ ELSE
+ JC = JDAHEP(2,JC)
+ ENDIF
+ ENDIF
+C--SEARCH IN THE JET
+ 600 CALL HWBRC2(COLP,IHEP,JC,.FALSE.,BVVUSE,.FALSE.)
+ IF(COLP.NE.0) THEN
+ IF(ABS(IDHEP(COLP)).EQ.6.AND.JDAHEP(1,COLP).NE.0) THEN
+ IF(ISTHEP(COLP).EQ.155) THEN
+ JC = JDAHEP(2,COLP)
+ ELSE
+ JC = JDAHEP(2,JDAHEP(2,COLP))
+ ENDIF
+ GOTO 600
+ ENDIF
+ JDAHEP(2,IHEP) = COLP
+ ENDIF
+ ELSE
+C--check if it came from a top
+ IF(ABS(IDHEP(JC)).EQ.6) THEN
+C--start the analysis again
+ JC = JMOHEP(1,IHEP)
+ IF(IST.NE.152) JC = JMOHEP(1,JC)
+ JC = JDAHEP(2,JC)
+ IF(JC.EQ.0) CALL HWWARN('HWBRCN',52,*610)
+ IF(ISTHEP(JC).EQ.155) THEN
+ IF (IDHEP(JMOHEP(1,JC)).EQ.94) THEN
+C---DECAYED BEFORE HADRONIZING
+ JHEP=JDAHEP(2,JC-1)
+ IF (JHEP.EQ.0) GO TO 610
+ ID=IDHW(JHEP)
+ IF (ISTHEP(JHEP).EQ.155) THEN
+C---SPECIAL FOR GLUINO DECAYS
+ IF (ID.EQ.449) THEN
+ CALL HWBRC1(JC,ID,JHEP,.TRUE.,*999)
+ ELSE
+ JC=JDAHEP(2,JHEP)
+ ENDIF
+ ELSE
+ IF(JMOHEP(2,JHEP).EQ.JC) JMOHEP(2,JHEP)=IHEP
+ JDAHEP(2,IHEP) = JHEP
+ GOTO 610
+ ENDIF
+ ELSE
+ JC=JDAHEP(2,JC-1)
+ ENDIF
+ ENDIF
+C--SEARCH IN JET
+ CALL HWBRC2(COLP,IHEP,JC,.FALSE.,BVVUSE,.FALSE.)
+ IF(COLP.NE.0) JDAHEP(2,IHEP) = COLP
+ ELSE
+ CALL HWWARN('HWBRCN',100,*610)
+ ENDIF
+ ENDIF
+ 610 CONTINUE
+ 999 END
+CDECK ID>, HWBRC1.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : PeterRichardson
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBRC1(JC,ID,JHEP,COL,*)
+C-----------------------------------------------------------------------
+C--Function to find the right daugther of a decaying gluino
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER ID,JHEP,KC,JC
+ LOGICAL COL
+C---N.B. WILL NEED MODS WHEN SUSY PARTICLES CAN SHOWER
+C--Rparity take the first daughther
+ IF(IDHW(JDAHEP(1,JHEP)).LE.12.AND.IDHW(JDAHEP(1,JHEP)+1).LE.12
+ & .AND.IDHW(JDAHEP(2,JHEP)).LE.12) THEN
+ KC = JDAHEP(1,JHEP)
+ GOTO 20
+ ELSEIF ((COL.AND.(ID.EQ.449.OR.ID.EQ.13)).OR.
+ & (ID.GE.401.AND.ID.LE.406).OR.
+ & (ID.GE.413.AND.ID.LE.418).OR.ID.LE.6.OR.
+ & (ID.GE.115.AND.ID.LE.120)) THEN
+C---LOOK FOR ANTI(S)QUARK OR GLUON
+ DO KC=JDAHEP(1,JHEP),JDAHEP(2,JHEP)
+ ID=IDHW(KC)
+ IF ((ID.GE.7.AND.ID.LE.13).OR.(ID.GE.407.AND.ID.LE.412).OR.
+ & (ID.GE.419.AND.ID.LE.424)) GOTO 20
+ ENDDO
+ ELSE
+C---LOOK FOR (S)QUARK OR GLUON
+ DO KC=JDAHEP(1,JHEP),JDAHEP(2,JHEP)
+ ID=IDHW(KC)
+ IF (ID.LE. 6.OR. ID.EQ. 13.OR.(ID.GE.401.AND.ID.LE.406).OR.
+ & (ID.GE.413.AND.ID.LE.418)) GOTO 20
+ ENDDO
+ ENDIF
+C---COULDNT FIND ONE
+ CALL HWWARN('HWBRC1',100,*10)
+ 10 RETURN 1
+ 20 JC=KC
+ END
+CDECK ID>, HWBRC2.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBRC2(COLP,IHEP,JC,CON,BVVUSE,BVVHRD)
+C-----------------------------------------------------------------------
+C--Function to search in the jet for the particle
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER JC,JD,QHEP,LHEP,IHEP,JHEP,IDM,NCOUNT,ID,IP,IDM2,COLP
+ LOGICAL CON,BVVUSE,FLA,AFLA,BVVHRD
+ FLA(IP) = (IP.LE.6.OR.(IP.GE.115.AND.IP.LE.120).
+ & OR.(IP.GE.401.AND.IP.LE.406).
+ & OR.(IP.GE.413.AND.IP.LE.418))
+ AFLA(IP) = ((IP.LE.12.AND.IP.GE.7).OR.(IP.GE.109.AND.IP.LE.114).
+ & OR.(IP.GE.407.AND.IP.LE.412).
+ & OR.(IP.GE.419.AND.IP.LE.424))
+ ID = IDHW(IHEP)
+ COLP = 0
+C--begining and end of jet
+ IF(JDAHEP(1,JC).NE.0) THEN
+ JC=JDAHEP(1,JC)
+ JD=JDAHEP(2,JC)
+ ELSE
+ COLP = JC
+ RETURN
+ ENDIF
+ IF (JD.LT.JC) JD=JC
+ LHEP=0
+ IF(CON) THEN
+C--SEARCH FOR A COLOUR PARTNER
+ DO 110 JHEP=JC,JD
+ IDM = IDHW(JHEP)
+ IF (ISTHEP(JHEP).LT.145.OR.ISTHEP(JHEP).GT.152) GOTO 110
+ IF(AFLA(ID).AND.IDM.EQ.13) GOTO 110
+ IF (JDAHEP(2,JHEP).EQ.IHEP) LHEP=JHEP
+ IF ((BVVUSE.AND.JMOHEP(2,JHEP).NE.0).OR.
+ & (.NOT.BVVUSE.AND.JDAHEP(2,JHEP).NE.0)) GOTO 110
+ IF(BVVUSE.AND.ABS(IDHEP(JHEP)).GT.1000000) THEN
+ IF(BVVHRD.AND.AFLA(ID)) THEN
+ CONTINUE
+ ELSE
+ RETURN
+ ENDIF
+ ENDIF
+ IF(BVVUSE.AND.(
+ & ((FLA(ID).OR.ID.EQ.13.OR.ID.EQ.449).AND.AFLA(IDM)).
+ & OR.(AFLA(ID).AND.(FLA(IDM).OR.IDM.EQ.13.OR.IDM.EQ.449))))
+ & GOTO 110
+ IF(AFLA(ID).AND.(IDM.EQ.59.OR.IDM.EQ.449.OR.IDM.EQ.13)) GOTO 110
+C---JOIN IHEP AND JHEP
+ COLP=JHEP
+ IF(BVVUSE.OR.(ID.GE.7.AND.ID.LE.12.
+ & AND.((IDM.GE.7.AND.IDM.LE.12)))) RETURN
+ IF(IHEP.NE.HRDCOL(1,2).AND.
+ & (((FLA(ID).OR.ID.EQ.13.OR.ID.EQ.449.OR.ID.EQ.59)
+ & .AND.(AFLA(IDM).OR.IDM.EQ.13.OR.IDM.EQ.449.OR.IDM.EQ.59))
+ & .OR.(AFLA(ID).AND.(FLA(IDM).OR.IDM.EQ.59))))
+ & JDAHEP(2,JHEP)=IHEP
+ RETURN
+ 110 CONTINUE
+ IF (LHEP.NE.0) COLP=LHEP
+C--Additional Baryon number violating piece
+ IF(COLP.EQ.0) THEN
+ IDM2= IDHW(JC)
+ IF(JMOHEP(1,JC).LT.6) THEN
+ IF(IDM2.LE.6) THEN
+ IDM2= IDM2+6
+ ELSEIF(IDM2.GT.6) THEN
+ IDM2=IDM2-6
+ ENDIF
+ ENDIF
+ IF(IHEP.EQ.HRDCOL(1,2).OR.
+ & ((FLA(ID).OR.ID.EQ.13.OR.ID.EQ.449.OR.ID.EQ.15.OR.ID.EQ.59)
+ & .AND.(AFLA(IDM2).OR.IDM2.EQ.13.OR.IDM2.EQ.13))) THEN
+ QHEP = JD+1
+ 12 QHEP = QHEP-1
+ IF(IDHEP(QHEP).EQ.0) GOTO 12
+ IF(IDHW(QHEP).EQ.59) THEN
+ IF(JC.EQ.JD.AND.IDHW(JMOHEP(1,QHEP)).EQ.59) THEN
+ COLP = IHEP
+ RETURN
+ ELSE
+ GOTO 12
+ ENDIF
+ ENDIF
+ NCOUNT = 0
+ 11 IF(JDAHEP(2,QHEP).NE.0) THEN
+ IF(JMOHEP(2,JDAHEP(2,QHEP)).EQ.QHEP.AND.
+ & JDAHEP(2,QHEP).NE.QHEP) THEN
+ IF(JDAHEP(2,QHEP).GE.JC.AND.JDAHEP(2,QHEP).LE.JD) THEN
+ QHEP = JDAHEP(2,QHEP)
+ NCOUNT = NCOUNT+1
+ IF(NCOUNT.LT.NHEP) GOTO 11
+ ENDIF
+ ENDIF
+ ENDIF
+ ELSE
+ QHEP = JC
+ 13 QHEP = QHEP+1
+ IF(IDHEP(QHEP).EQ.0) GOTO 13
+ IF(IDHW(QHEP).EQ.59) THEN
+ IF(JC.EQ.JD.AND.IDHW(JMOHEP(1,QHEP)).EQ.59) THEN
+ COLP = IHEP
+ RETURN
+ ELSE
+ GOTO 13
+ ENDIF
+ ENDIF
+ NCOUNT = 0
+ 9 IF(JMOHEP(2,QHEP).NE.0) THEN
+ IF(JDAHEP(2,JMOHEP(2,QHEP)).EQ.QHEP.AND.
+ & JMOHEP(2,QHEP).NE.QHEP) THEN
+ IF(JMOHEP(2,QHEP).GE.JC.AND.JMOHEP(2,QHEP).LE.JD) THEN
+ QHEP = JMOHEP(2,QHEP)
+ NCOUNT = NCOUNT+1
+ IF(NCOUNT.LT.NHEP) GOTO 9
+ ENDIF
+ ENDIF
+ ENDIF
+ ENDIF
+ IF(ABS(IDHEP(QHEP)).LT.1000000) COLP=QHEP
+ ENDIF
+ ELSE
+C--Search for an anticolour partner
+ DO 210 JHEP=JC,JD
+ IF (ISTHEP(JHEP).LT.145.OR.ISTHEP(JHEP).GT.152) GOTO 210
+ IF (JMOHEP(2,JHEP).EQ.IHEP) LHEP=JHEP
+ IF (JMOHEP(2,JHEP).NE.0) GOTO 210
+C---JOIN IHEP AND JHEP
+ COLP=JHEP
+ RETURN
+ 210 CONTINUE
+ IF (LHEP.NE.0) COLP=LHEP
+C--New piece
+ IF(COLP.EQ.0) THEN
+ IDM2=IDHW(JC)
+ IF(JMOHEP(1,JC).LT.6) THEN
+ IF(IDM2.LE.6) THEN
+ IDM2= IDM2+6
+ ELSEIF(IDM2.GT.6) THEN
+ IDM2=IDM2-6
+ ENDIF
+ ENDIF
+C--Additional Baryon number violating piece
+ IF((FLA(ID).AND.AFLA(IDM2)).OR.
+ & ((AFLA(ID).OR.ID.EQ.13.OR.ID.EQ.449.OR.ID.EQ.15.OR.ID.EQ.59)
+ & .AND.(FLA(IDM2).OR.IDM2.EQ.13.OR.IDM2.EQ.449))) THEN
+ QHEP = JC
+ 211 QHEP = QHEP+1
+ IF(IDHEP(QHEP).EQ.0) GOTO 211
+ IF(IDHW(QHEP).EQ.59) THEN
+ IF(JC.EQ.JD.AND.IDHW(JMOHEP(1,QHEP)).EQ.59) THEN
+ COLP = IHEP
+ RETURN
+ ELSE
+ GOTO 211
+ ENDIF
+ ENDIF
+ NCOUNT = 0
+ 209 IF(JMOHEP(2,QHEP).NE.0) THEN
+ IF(JDAHEP(2,JMOHEP(2,QHEP)).EQ.QHEP.AND.
+ & JMOHEP(2,QHEP).NE.QHEP) THEN
+ IF(JMOHEP(2,QHEP).GE.JC.AND.JMOHEP(2,QHEP).LE.JD) THEN
+ QHEP = JMOHEP(2,QHEP)
+ NCOUNT = NCOUNT+1
+ IF(NCOUNT.LT.NHEP) GOTO 209
+ ENDIF
+ ENDIF
+ ENDIF
+ IF(QHEP.NE.0) COLP=QHEP
+ IF(JDAHEP(2,QHEP).EQ.0.AND.IHEP.NE.6) THEN
+ IDM2= IDHW(QHEP)
+ IF(FLA(IHEP).AND.FLA(QHEP).OR.
+ & ((AFLA(IHEP).OR.ID.EQ.13.OR.ID.EQ.449).AND.
+ & (AFLA(QHEP).OR.IDM2.EQ.13.OR.IDM2.EQ.449)))
+ & JDAHEP(2,QHEP)=IHEP
+ ENDIF
+ ELSE
+ QHEP = JD+1
+ 220 QHEP = QHEP-1
+ IF(IDHEP(QHEP).EQ.0) GOTO 220
+ IF(IDHW(QHEP).EQ.59) THEN
+ IF(JC.EQ.JD.AND.IDHW(JMOHEP(1,QHEP)).EQ.59) THEN
+ COLP = IHEP
+ RETURN
+ ELSE
+ GOTO 220
+ ENDIF
+ ENDIF
+ NCOUNT = 0
+ 219 IF(JDAHEP(2,QHEP).NE.0) THEN
+ IF(JMOHEP(2,JDAHEP(2,QHEP)).EQ.QHEP) THEN
+ IF(JDAHEP(2,QHEP).GE.JC.AND.JDAHEP(2,QHEP).LE.JD) THEN
+ QHEP = JDAHEP(2,QHEP)
+ NCOUNT = NCOUNT+1
+ IF(NCOUNT.LT.200) GOTO 219
+ ENDIF
+ ENDIF
+ ENDIF
+ IF(QHEP.NE.0) COLP=QHEP
+ IDM2 = IDHW(QHEP)
+ IF(JDAHEP(2,QHEP).EQ.0.AND.
+ & (((AFLA(ID).OR.ID.EQ.13).AND.(AFLA(IDM2).OR.IDM2.EQ.13)).OR.
+ & (FLA(ID).AND.FLA(IDM2)))) JDAHEP(2,QHEP)=IHEP
+ ENDIF
+ ENDIF
+ ENDIF
+ END
+CDECK ID>, HWBSPA.
+*CMZ :- -26/04/91 14.26.44 by Federico Carminati
+*-- Author : Ian Knowles
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBSPA
+C-----------------------------------------------------------------------
+C Constructs time-like 4-momenta & production vertices in space-like
+C jet started by parton no.2 interference partner 1 and spin density
+C DECPAR(2). RHOPAR(2) gives the jet spin density matrix.
+C See I.G. Knowles, Comp. Phys. Comm. 58 (90) 271.
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWR,DMIN,PT,EIKON,EISCR,EINUM,EIDEN1,EIDEN2,
+ & WT,SPIN,Z1,Z2,TR,PRMAX,CX,SX,CAZ,ROHEP(3),RMAT(3,3),ZERO2(2)
+ INTEGER JPAR,KPAR,LPAR,MPAR
+ LOGICAL EICOR
+ EXTERNAL HWR
+ DATA ZERO2,DMIN/ZERO,ZERO,1.D-15/
+ IF (IERROR.NE.0) RETURN
+ JPAR=2
+ KPAR=1
+ IF (NPAR.EQ.2) THEN
+ CALL HWVZRO(2,RHOPAR(1,2))
+ RETURN
+ ENDIF
+C Generate azimuthal angle of JPAR's branching using an M-function
+C Find the daughters of JPAR, with LPAR time-like
+ 10 LPAR=JDAPAR(1,JPAR)
+ IF (TMPAR(LPAR)) THEN
+ MPAR=LPAR+1
+ ELSE
+ MPAR=LPAR
+ LPAR=MPAR+1
+ ENDIF
+C Soft correlations
+ CALL HWUROT(PPAR(1,JPAR), ONE,ZERO,RMAT)
+ CALL HWUROF(RMAT,PPAR(1,KPAR),ROHEP)
+ PT=MAX(SQRT(ROHEP(1)*ROHEP(1)+ROHEP(2)*ROHEP(2)),DMIN)
+ EIKON=1.
+ EICOR=AZSOFT.AND.IDPAR(LPAR).EQ.13
+ IF (EICOR) THEN
+ EISCR=1.-PPAR(5,MPAR)*PPAR(5,MPAR)/(MIN(PPAR(2,LPAR),
+ & PPAR(2,MPAR))*PPAR(4,MPAR)*PPAR(4,MPAR))
+ EINUM=PPAR(4,KPAR)*PPAR(4,LPAR)*ABS(PPAR(2,LPAR)-PPAR(2,MPAR))
+ EIDEN1=PPAR(4,KPAR)*PPAR(4,LPAR)-ROHEP(3)*PPAR(3,LPAR)
+ EIDEN2=PT*ABS(PPAR(1,LPAR))
+ EIKON=MAX(EISCR+EINUM/MAX(EIDEN1-EIDEN2,DMIN),ZERO)
+ ENDIF
+C Spin correlations
+ WT=0.
+ SPIN=1.
+ IF (AZSPIN.AND.IDPAR(JPAR).EQ.13) THEN
+ Z1=PPAR(4,JPAR)/PPAR(4,MPAR)
+ Z2=1.-Z1
+ IF (IDPAR(MPAR).EQ.13) THEN
+ TR=Z1/Z2+Z2/Z1+Z1*Z2
+ ELSEIF (IDPAR(MPAR).LT.13) THEN
+ TR=(Z1*Z1+Z2*Z2)/2.
+ ENDIF
+ WT=Z2/(Z1*TR)
+ ENDIF
+C Assign the azimuthal angle
+ PRMAX=(1.+ABS(WT))*EIKON
+ 50 CALL HWRAZM( ONE,CX,SX)
+ CALL HWUROT(PPAR(1,JPAR),CX,SX,RMAT)
+C Determine the angle between the branching planes
+ CALL HWUROF(RMAT,PPAR(1,KPAR),ROHEP)
+ CAZ=ROHEP(1)/PT
+ PHIPAR(1,JPAR)=2.*CAZ*CAZ-1.
+ PHIPAR(2,JPAR)=2.*CAZ*ROHEP(2)/PT
+ IF (EICOR) EIKON=MAX(EISCR+EINUM/MAX(EIDEN1-EIDEN2*CAZ,DMIN),ZERO)
+ IF (AZSPIN) SPIN=1.+WT*(DECPAR(1,JPAR)*PHIPAR(1,JPAR)
+ & +DECPAR(2,JPAR)*PHIPAR(2,JPAR))
+ IF (SPIN*EIKON.LT.HWR()*PRMAX) GOTO 50
+C Construct full 4-momentum of LPAR, sum P-trans of MPAR
+ PPAR(2,LPAR)=0.
+ PPAR(2,MPAR)=0.
+ CALL HWUROB(RMAT,PPAR(1,LPAR),PPAR(1,LPAR))
+ CALL HWVDIF(2,PPAR(1,2),PPAR(1,LPAR),PPAR(1,2))
+C Test for end of space-like branches
+ IF (JDAPAR(1,MPAR).EQ.0) GOTO 60
+C Generate new Decay matrix
+ CALL HWBAZF(MPAR,JPAR,ZERO2,DECPAR(1,JPAR),
+ & PHIPAR(1,JPAR),DECPAR(1,MPAR))
+C Advance along the space-like branch
+ JPAR=MPAR
+ KPAR=LPAR
+ GOTO 10
+C Retreat along space-like line
+C Assign initial spin density matrix
+ 60 CALL HWVEQU(2,ZERO2,RHOPAR(1,MPAR))
+ CALL HWUMAS(PPAR(1,2))
+ CALL HWVZRO(4,VPAR(1,MPAR))
+ 70 CALL HWVEQU(4,VPAR(1,MPAR),VPAR(1,LPAR))
+ IF (MPAR.EQ.2) RETURN
+C Construct spin density matrix for time-like branch
+ CALL HWBAZF(MPAR,JPAR,RHOPAR(1,MPAR),PHIPAR(1,JPAR),
+ & DECPAR(1,JPAR),RHOPAR(1,LPAR))
+C Evolve time-like side branch
+ CALL HWBTIM(LPAR,MPAR)
+C Construct spin density matrix for space-like branch
+ CALL HWBAZF(MPAR,JPAR,PHIPAR(1,JPAR),RHOPAR(1,MPAR),
+ & DECPAR(1,LPAR),RHOPAR(1,JPAR))
+C Assign production vertex to J
+ CALL HWVDIF(4,PPAR(1,MPAR),PPAR(1,LPAR),PPAR(1,JPAR))
+ CALL HWUDKL(IDPAR(JPAR),PPAR(1,JPAR),VPAR(1,JPAR))
+ CALL HWVSUM(4,VPAR(1,MPAR),VPAR(1,JPAR),VPAR(1,JPAR))
+C Find parent and partner of MPAR
+ MPAR=JPAR
+ JPAR=JMOPAR(1,MPAR)
+ LPAR=MPAR+1
+ IF (JMOPAR(1,LPAR).NE.JPAR) LPAR=MPAR-1
+ GOTO 70
+ END
+CDECK ID>, HWBSPN.
+*CMZ :- -26/04/91 11.11.54 by Bryan Webber
+*-- Author : Ian Knowles
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBSPN
+C-----------------------------------------------------------------------
+C Constructs appropriate spin density/decay matrix for parton
+C in hard subprocess, othwise zero. Assignments based upon
+C Comp. Phys. Comm. 58 (1990) 271.
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION C,V12,V23,V13,TR,C1,C2,C3,R1(2),R2(2)
+ INTEGER IST
+ SAVE R1,R2,V12
+ IF (IERROR.NE.0) RETURN
+ IST=MOD(ISTHEP(NEVPAR),10)
+C Assumed partons processed in the order IST=1,2,3,4
+ IF (IPROC.GE.100.AND.IPROC.LE.116) THEN
+C An e+e- ---> qqbar g event
+ IF (IDPAR(2).EQ.13) THEN
+ RHOPAR(1,2)=GPOLN
+ RHOPAR(2,2)=0.
+ RETURN
+ ENDIF
+ ELSEIF (IPRO.EQ.15.OR.IPRO.EQ.17) THEN
+ IF (IHPRO.EQ. 7.OR.IHPRO.EQ. 8.OR.
+ & IHPRO.EQ.10.OR.IHPRO.EQ.11.OR.
+ & IHPRO.EQ.15.OR.IHPRO.EQ.16.OR.
+ & (IHPRO.GE.21.AND.IHPRO.LE.31)) THEN
+C A hard 2 --- > 2 QCD subprocess involving gluons
+ IF (IST.EQ.2) THEN
+ CALL HWVEQU(2,RHOPAR(1,2),R1(1))
+ C=GCOEF(2)/GCOEF(1)
+ DECPAR(1,2)=C*R1(1)
+ DECPAR(2,2)=C*R1(2)
+ RETURN
+ ELSEIF (IST.EQ.3) THEN
+ CALL HWVEQU(2,RHOPAR(1,2),R2(1))
+ V12=R1(1)*R2(1)+R1(2)*R2(2)
+ TR=1./(GCOEF(1)+GCOEF(2)*V12)
+ RHOPAR(1,2)= (GCOEF(3)*R1(1)+GCOEF(4)*R2(1))*TR
+ RHOPAR(2,2)=-(GCOEF(3)*R1(2)+GCOEF(4)*R2(2))*TR
+ RETURN
+ ELSEIF (IST.EQ.4) THEN
+ V13=R1(1)*DECPAR(1,2)+R1(2)*DECPAR(2,2)
+ V23=R2(1)*DECPAR(1,2)+R2(2)*DECPAR(2,2)
+ TR=1./(GCOEF(1)+GCOEF(2)*V12+GCOEF(3)*V13+GCOEF(4)*V23)
+ C1=(GCOEF(2)+GCOEF(5))*TR
+ C2=(GCOEF(3)+GCOEF(6))*TR
+ C3=(GCOEF(4)+GCOEF(6))*TR
+ RHOPAR(1,2)=C1*DECPAR(1,2)+C2*R2(1)+C3*R1(1)
+ RHOPAR(2,2)=C1*DECPAR(2,2)-C2*R1(2)-C3*R2(2)
+ RETURN
+ ENDIF
+ ENDIF
+ ELSEIF (IPRO.EQ.16) THEN
+C A gluon fusion ---> Higgs event
+ IF (IST.EQ.2) THEN
+ DECPAR(1,2)=RHOPAR(1,2)
+ DECPAR(2,2)=-RHOPAR(2,2)
+ RETURN
+ ENDIF
+ ENDIF
+ CALL HWVZRO(2,RHOPAR(1,2))
+ CALL HWVZRO(2,DECPAR(1,2))
+ END
+CDECK ID>, HWBSU1.
+*CMZ :- -13/07/92 20.15.54 by Mike Seymour
+*-- Author : Bryan Webber, modified by Mike Seymour
+C-----------------------------------------------------------------------
+ FUNCTION HWBSU1(ZLOG)
+C-----------------------------------------------------------------------
+C Z TIMES THE INTEGRAND IN EXPONENT OF QUARK SUDAKOV FORM FACTOR.
+C HWBSU1 IS FOR UPPER PART OF Z INTEGRATION REGION
+C-----------------------------------------------------------------------
+ DOUBLE PRECISION HWBSU1,HWBSUL,Z,ZLOG,U
+ EXTERNAL HWBSUL
+ Z=EXP(ZLOG)
+ U=1.-Z
+ HWBSU1=HWBSUL(Z)*(1.+U*U)
+ END
+CDECK ID>, HWBSU2.
+*CMZ :- -13/07/92 20.15.54 by Mike Seymour
+*-- Author : Bryan Webber, modified by Mike Seymour
+C-----------------------------------------------------------------------
+ FUNCTION HWBSU2(Z)
+C-----------------------------------------------------------------------
+C INTEGRAND IN EXPONENT OF QUARK SUDAKOV FORM FACTOR.
+C HWBSU2 IS FOR LOWER PART OF Z INTEGRATION REGION
+C-----------------------------------------------------------------------
+ DOUBLE PRECISION HWBSU2,HWBSUL,Z,U
+ EXTERNAL HWBSUL
+ U=1.-Z
+ HWBSU2=HWBSUL(Z)*(1.+Z*Z)/U
+ END
+CDECK ID>, HWBSUD.
+*CMZ :- -14/07/92 13.28.23 by Mike Seymour
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBSUD
+C-----------------------------------------------------------------------
+C COMPUTES (OR READS) TABLES OF SUDAKOV FORM FACTORS
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWUGAU,HWBVMC,HWBSUG,HWBSU1,HWBSU2,G1,G2,QRAT,
+ & QLAM,POWER,AFAC,QMIN,QFAC,QNOW,ZMIN,ZMAX,Q1,QCOLD,VGOLD,VQOLD,
+ & RMOLD(6),ACOLD,ZLO,ZHI
+ INTEGER IQ,IS,L1,L2,L,LL,I,INOLD,NQOLD,NSOLD,NCOLD,NFOLD,SDOLD
+ EXTERNAL HWUGAU,HWBVMC,HWBSUG,HWBSU1,HWBSU2
+ SAVE NQOLD,NSOLD,NCOLD,NFOLD,SDOLD,QCOLD,VGOLD,VQOLD,RMOLD,ACOLD
+ COMMON/HWSINT/QRAT,QLAM
+ IF (LRSUD.EQ.0) THEN
+ POWER=1./FLOAT(NQEV-1)
+ AFAC=6.*CAFAC/BETAF
+ QMIN=QG+QG
+ QFAC=(1.1*QLIM/QMIN)**POWER
+ SUD(1,1)=1.
+ QEV(1,1)=QMIN
+C--IS=1 FOR GLUON->GLUON+GLUON FORM FACTOR
+ DO 10 IQ=2,NQEV
+ QNOW=QFAC*QEV(IQ-1,1)
+ QLAM=QNOW/QCDL3
+ ZMIN=QG/QNOW
+ QRAT=1./ZMIN
+ G1=0
+ DO 5 I=3,6
+ ZLO=ZMIN
+ ZHI=HALF
+ IF (I.NE.6) ZLO=MAX(ZLO,QG/RMASS(I+1))
+ IF (I.NE.3) ZHI=MIN(ZHI,QG/RMASS(I))
+ IF (ZHI.GT.ZLO) G1=G1+HWUGAU(HWBSUG,LOG(ZLO),LOG(ZHI),ACCUR)
+ 5 CONTINUE
+ SUD(IQ,1)=EXP(AFAC*G1)
+ 10 QEV(IQ,1)=QNOW
+ AFAC=3.*CFFAC/BETAF
+C--QUARK FORM FACTORS.
+C--IS=2,3,4,5,6,7 FOR U/D,S,C,B,T,V
+ DO 15 IS=2,NSUD
+ Q1=HWBVMC(IS)
+ IF (IS.EQ.7) Q1=HWBVMC(209)
+ QMIN=Q1+QG
+ IF (QMIN.GT.QLIM) GOTO 15
+ QFAC=(1.1*QLIM/QMIN)**POWER
+ SUD(1,IS)=1.
+ QEV(1,IS)=QMIN
+ DO 14 IQ=2,NQEV
+ QNOW=QFAC*QEV(IQ-1,IS)
+ QLAM=QNOW/QCDL3
+ ZMIN=QG/QNOW
+ QRAT=1./ZMIN
+ ZMAX=QG/QMIN
+ G1=0
+ DO 12 I=3,6
+ ZLO=ZMIN
+ ZHI=ZMAX
+ IF (I.NE.6) ZLO=MAX(ZLO,QG/RMASS(I+1))
+ IF (I.NE.3) ZHI=MIN(ZHI,QG/RMASS(I))
+ IF (ZHI.GT.ZLO) G1=G1+HWUGAU(HWBSU1,LOG(ZLO),LOG(ZHI),ACCUR)
+ 12 CONTINUE
+ ZMIN=Q1/QNOW
+ QRAT=1./ZMIN
+ ZMAX=Q1/QMIN
+ G2=0
+ DO 13 I=3,6
+ ZLO=ZMIN
+ ZHI=ZMAX
+ IF (I.NE.6) ZLO=MAX(ZLO,Q1/RMASS(I+1))
+ IF (I.NE.3) ZHI=MIN(ZHI,Q1/RMASS(I))
+ IF (ZHI.GT.ZLO) G2=G2+HWUGAU(HWBSU2,ZLO,ZHI,ACCUR)
+ 13 CONTINUE
+ SUD(IQ,IS)=EXP(AFAC*(G1+G2))
+ 14 QEV(IQ,IS)=QNOW
+ 15 CONTINUE
+ QCOLD=QCDLAM
+ VGOLD=VGCUT
+ VQOLD=VQCUT
+ ACOLD=ACCUR
+ INOLD=INTER
+ NQOLD=NQEV
+ NSOLD=NSUD
+ NCOLD=NCOLO
+ NFOLD=NFLAV
+ SDOLD=SUDORD
+ DO 16 IS=1,NSUD
+ 16 RMOLD(IS)=RMASS(IS)
+ ELSE
+ IF (LRSUD.GT.0) THEN
+ IF (IPRINT.NE.0) WRITE (6,17) LRSUD
+ 17 FORMAT(10X,'READING SUDAKOV TABLE ON UNIT',I4)
+ OPEN(UNIT=LRSUD,FORM='UNFORMATTED',STATUS='UNKNOWN')
+ READ(UNIT=LRSUD) QCOLD,VGOLD,VQOLD,RMOLD,
+ & ACOLD,QEV,SUD,INOLD,NQOLD,NSOLD,NCOLD,NFOLD,SDOLD
+ CLOSE(UNIT=LRSUD)
+ ENDIF
+C---CHECK THAT RELEVANT PARAMETERS ARE UNCHANGED
+ IF (QCDLAM.NE.QCOLD) CALL HWWARN('HWBSUD',501,*999)
+ IF (VGCUT .NE.VGOLD) CALL HWWARN('HWBSUD',502,*999)
+ IF (VQCUT .NE.VQOLD) CALL HWWARN('HWBSUD',503,*999)
+ IF (ACCUR .NE.ACOLD) CALL HWWARN('HWBSUD',504,*999)
+ IF (INTER .NE.INOLD) CALL HWWARN('HWBSUD',505,*999)
+ IF (NQEV .NE.NQOLD) CALL HWWARN('HWBSUD',506,*999)
+ IF (NSUD .NE.NSOLD) CALL HWWARN('HWBSUD',507,*999)
+ IF (NCOLO .NE.NCOLD) CALL HWWARN('HWBSUD',508,*999)
+ IF (NFLAV .NE.NFOLD) CALL HWWARN('HWBSUD',509,*999)
+ IF (SUDORD.NE.SDOLD) CALL HWWARN('HWBSUD',510,*999)
+C---CHECK MASSES AND THAT TABLES ARE BIG ENOUGH FOR THIS RUN
+ DO 18 IS=1,NSUD
+ IF (RMASS(IS).NE.RMOLD(IS))
+ & CALL HWWARN('HWBSUD',510+IS,*999)
+ IF (QEV(NQEV,IS).LT.QLIM.AND.HWBVMC(IS)+QG.LT.QLIM)
+ & CALL HWWARN('HWBSUD',500,*999)
+ 18 CONTINUE
+ ENDIF
+ IF (LWSUD.GT.0) THEN
+ IF (IPRINT.NE.0) WRITE (6,19) LWSUD
+ 19 FORMAT(10X,'WRITING SUDAKOV TABLE ON UNIT',I4)
+ OPEN (UNIT=LWSUD,FORM='UNFORMATTED',STATUS='UNKNOWN')
+ WRITE(UNIT=LWSUD) QCDLAM,VGCUT,VQCUT,(RMASS(I),I=1,6),
+ & ACCUR,QEV,SUD,INTER,NQEV,NSUD,NCOLO,NFLAV,SUDORD
+ CLOSE(UNIT=LWSUD)
+ ENDIF
+ IF (IPRINT.GT.2) THEN
+C--PRINT EXTRACTS FROM TABLES OF FORM FACTORS
+ DO 40 IS=1,NSUD
+ WRITE(6,20) IS,NQEV
+ 20 FORMAT(1H1//10X,'EXTRACT FROM TABLE OF SUDAKOV FORM FACTOR NO.',
+ & I2,' (',I5,' ACTUAL ENTRIES)'//10X,'SUD IS PROBABILITY THAT',
+ & ' PARTON WITH GIVEN UPPER LIMIT ON Q WILL REACH THRESHOLD',
+ & ' WITHOUT BRANCHING'///2X,8(' Q SUD ')/)
+ L2=NQEV/8
+ L1=L2/32
+ IF (L1.LT.1) L1=1
+ DO 40 L=L1,L2,L1
+ LL=L+7*L2
+ WRITE(6,30) (QEV(I,IS),SUD(I,IS),I=L,LL,L2)
+ 30 FORMAT(2X,8(F9.2,F7.4))
+ 40 CONTINUE
+ WRITE(6,50)
+ 50 FORMAT(1H1)
+ ENDIF
+ 999 END
+CDECK ID>, HWBSUG.
+*CMZ :- -13/07/92 20.15.54 by Mike Seymour
+*-- Author : Bryan Webber, modified by Mike Seymour
+C-----------------------------------------------------------------------
+ FUNCTION HWBSUG(ZLOG)
+C-----------------------------------------------------------------------
+C Z TIMES INTEGRAND IN EXPONENT OF GLUON SUDAKOV FORM FACTOR
+C-----------------------------------------------------------------------
+ DOUBLE PRECISION HWBSUG,HWBSUL,Z,ZLOG,W
+ EXTERNAL HWBSUL
+ Z=EXP(ZLOG)
+ W=Z*(1.-Z)
+ HWBSUG=HWBSUL(Z)*(W-2.+1./W)*Z
+ END
+CDECK ID>, HWBSUL.
+*CMZ :- -13/07/92 20.15.54 by Mike Seymour
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ FUNCTION HWBSUL(Z)
+C-----------------------------------------------------------------------
+C LOGARITHMIC PART OF INTEGRAND IN EXPONENT OF SUDAKOV FORM FACTOR.
+C THE SECOND ORDER ALPHAS CASE COMES FROM CONVERTING INTEGRAL OVER
+C Q^2 INTO ONE OVER ALPHAS, WITH FLAVOUR THRESHOLDS.
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWBSUL,HWUALF,Z,QRAT,QLAM,U,AL,BL,QNOW,QMIN,
+ & BET(6),BEP(6),MUMI(6),MUMA(6),ALMI(6),ALMA(6),FINT(6),ALFINT,
+ & MUMIN,MUMAX,ALMIN,ALMAX
+ INTEGER NF
+ LOGICAL FIRST
+ EXTERNAL HWUALF
+ SAVE FIRST,BET,BEP,MUMI,MUMA
+ COMMON/HWSINT/QRAT,QLAM
+ DATA FIRST/.TRUE./
+ ALFINT(AL,BL)=1/BET(NF)*
+ & LOG(BL/(AL*(1+BEP(NF)*BL))*(1+BEP(NF)*AL))
+ HWBSUL=0
+ U=1.-Z
+ IF (SUDORD.EQ.1) THEN
+ AL=LOG(QRAT*Z)
+ BL=LOG(QLAM*U*Z)
+ HWBSUL=LOG(1.-AL/BL)
+ ELSE
+ IF (FIRST) THEN
+ DO 10 NF=3,6
+ BET(NF)=(11*CAFAC-2*NF)/(12*PIFAC)
+ BEP(NF)=(17*CAFAC**2-(5*CAFAC+3*CFFAC)*NF)/(24*PIFAC**2)
+ & /BET(NF)
+ IF (NF.EQ.3) THEN
+ MUMI(3)=0
+ ALMI(3)=1D30
+ ELSE
+ MUMI(NF)=RMASS(NF)
+ ALMI(NF)=HWUALF(1,MUMI(NF))
+ ENDIF
+ IF (NF.EQ.6) THEN
+ MUMA(NF)=1D30
+ ALMA(NF)=0
+ ELSE
+ MUMA(NF)=RMASS(NF+1)
+ ALMA(NF)=HWUALF(1,MUMA(NF))
+ ENDIF
+ IF (NF.NE.3.AND.NF.NE.6) FINT(NF)=ALFINT(ALMI(NF),ALMA(NF))
+ 10 CONTINUE
+ FIRST=.FALSE.
+ ENDIF
+ QNOW=QLAM*QCDL3
+ QMIN=QNOW/QRAT
+ MUMIN= U*QMIN
+ MUMAX=Z*U*QNOW
+ IF (MUMAX.LE.MUMIN) RETURN
+ ALMIN=HWUALF(1,MUMIN)
+ ALMAX=HWUALF(1,MUMAX)
+ NF=3
+ 20 IF (MUMIN.GT.MUMA(NF)) THEN
+ NF=NF+1
+ GOTO 20
+ ENDIF
+ IF (MUMAX.LT.MUMA(NF)) THEN
+ HWBSUL=ALFINT(ALMIN,ALMAX)
+ ELSE
+ HWBSUL=ALFINT(ALMIN,ALMA(NF))
+ NF=NF+1
+ 30 IF (MUMAX.GT.MUMA(NF)) THEN
+ HWBSUL=HWBSUL+FINT(NF)
+ NF=NF+1
+ GOTO 30
+ ENDIF
+ HWBSUL=HWBSUL+ALFINT(ALMI(NF),ALMAX)
+ ENDIF
+ HWBSUL=HWBSUL*BET(5)
+ ENDIF
+ END
+CDECK ID>, HWBTIM.
+*CMZ :- -26/04/91 14.27.17 by Federico Carminati
+*-- Author : Ian Knowles
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBTIM(INITBR,INTERF)
+C-----------------------------------------------------------------------
+C Constructs full 4-momentum & production vertices in time-like jet
+C initiated by INITBR, interference partner INTERF and spin density
+C RHOPAR(INITBR). DECPAR(INITBR) returns jet's spin density matrix.
+C Includes azimuthal angular correlations between branching planes
+C due to spin (if AZSPIN) using the algorithm of Knowles & Collins.
+C Ses Nucl. Phys. B304 (1988) 794 & Comp. Phys. Comm. 58 (1990) 271.
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWR,DMIN,PT,EIKON,EINUM,EIDEN1,EIDEN2,EISCR,
+ & WT,SPIN,Z1,Z2,PRMAX,CAZ,CX,SX,ROHEP(3),RMAT(3,3),ZERO2(2)
+ INTEGER INITBR,INTERF,IPAR,JPAR,KPAR,LPAR,MPAR,NTRY,JOLD
+ LOGICAL EICOR,SWAP
+ EXTERNAL HWR
+ DATA ZERO2,DMIN/ZERO,ZERO,1.D-15/
+ IF (IERROR.NE.0) RETURN
+ JPAR=INITBR
+ KPAR=INTERF
+ IF ((JDAPAR(1,JPAR).NE.0).OR.(IDPAR(JPAR).EQ.13)) GOTO 30
+C No branching, assign decay matrix
+ CALL HWVZRO(2,DECPAR(1,JPAR))
+ RETURN
+C Advance up the leader
+C Find the parent and partner of J
+ 10 IPAR=JMOPAR(1,JPAR)
+ KPAR=JPAR+1
+C Generate new Rho
+ IF (JMOPAR(1,KPAR).EQ.IPAR) THEN
+C Generate Rho'
+ CALL HWBAZF(IPAR,JPAR,PHIPAR(1,IPAR),RHOPAR(1,IPAR),
+ & ZERO2,RHOPAR(1,JPAR))
+ ELSE
+ KPAR=JPAR-1
+ IF (JMOPAR(1,KPAR).NE.IPAR)
+ & CALL HWWARN('HWBTIM',100,*999)
+C Generate Rho''
+ CALL HWBAZF(IPAR,KPAR,RHOPAR(1,IPAR),PHIPAR(1,IPAR),
+ & DECPAR(1,KPAR),RHOPAR(1,JPAR))
+ ENDIF
+C Generate azimuthal angle of J's branching
+ 30 IF (JDAPAR(1,JPAR).EQ.0) THEN
+C Final state gluon
+ CALL HWVZRO(2,DECPAR(1,JPAR))
+ IF (JPAR.EQ.INITBR) RETURN
+ GOTO 70
+ ELSE
+C Assign an angle to a branching using an M-function
+C Find the daughters of J
+ LPAR=JDAPAR(1,JPAR)
+ MPAR=JDAPAR(2,JPAR)
+C Soft correlations
+ CALL HWUROT(PPAR(1,JPAR), ONE,ZERO,RMAT)
+ CALL HWUROF(RMAT,PPAR(1,KPAR),ROHEP)
+ PT=MAX(SQRT(ROHEP(1)*ROHEP(1)+ROHEP(2)*ROHEP(2)),DMIN)
+ EIKON=1.
+ SWAP=.FALSE.
+ EICOR=AZSOFT.AND.((IDPAR(LPAR).EQ.13).OR.(IDPAR(MPAR).EQ.13))
+ IF (EICOR) THEN
+C Rearrange s.t. LPAR is the (softest) gluon
+ IF (IDPAR(MPAR).EQ.13) THEN
+ IF (IDPAR(LPAR).NE.13.OR.
+ & PPAR(4,MPAR).LT.PPAR(4,LPAR)) THEN
+ SWAP=.TRUE.
+ LPAR=MPAR
+ MPAR=LPAR-1
+ ENDIF
+ ENDIF
+ EINUM=(PPAR(4,KPAR)*PPAR(4,LPAR))
+ & *ABS(PPAR(2,LPAR)-PPAR(2,MPAR))
+ EIDEN1=(PPAR(4,KPAR)*PPAR(4,LPAR))-ROHEP(3)*PPAR(3,LPAR)
+ EIDEN2=PT*ABS(PPAR(1,LPAR))
+ EISCR=1.-(PPAR(5,MPAR)/PPAR(4,MPAR))**2
+ & /MIN(PPAR(2,LPAR),PPAR(2,MPAR))
+ EIKON=EISCR+EINUM/MAX(EIDEN1-EIDEN2,DMIN)
+ ENDIF
+C Spin correlations
+ WT=0.
+ SPIN=1.
+ IF (AZSPIN) THEN
+ Z1=PPAR(4,LPAR)/PPAR(4,JPAR)
+ Z2=1.-Z1
+ IF (IDPAR(JPAR).EQ.13.AND.IDPAR(LPAR).EQ.13) THEN
+ WT=Z1*Z2/(Z1/Z2+Z2/Z1+Z1*Z2)
+ ELSEIF (IDPAR(JPAR).EQ.13.AND.IDPAR(LPAR).LT.13) THEN
+ WT=-2.*Z1*Z2/(Z1*Z1+Z2*Z2)
+ ENDIF
+ ENDIF
+C Assign the azimuthal angle
+ PRMAX=(1.+ABS(WT))*EIKON
+ NTRY=0
+ 50 NTRY=NTRY+1
+ IF (NTRY.GT.NBTRY) CALL HWWARN('HWBTIM',101,*999)
+ CALL HWRAZM( ONE,CX,SX)
+ CALL HWUROT(PPAR(1,JPAR),CX,SX,RMAT)
+C Determine the angle between the branching planes
+ CALL HWUROF(RMAT,PPAR(1,KPAR),ROHEP)
+ CAZ=ROHEP(1)/PT
+ PHIPAR(1,JPAR)=2.*CAZ*CAZ-1.
+ PHIPAR(2,JPAR)=2.*CAZ*ROHEP(2)/PT
+ IF (EICOR) EIKON=EISCR+EINUM/MAX(EIDEN1-EIDEN2*CAZ,DMIN)
+ IF (AZSPIN) SPIN=1.+WT*(RHOPAR(1,JPAR)*PHIPAR(1,JPAR)
+ & +RHOPAR(2,JPAR)*PHIPAR(2,JPAR))
+ IF (SPIN*EIKON.LT.HWR()*PRMAX) GOTO 50
+C Construct full 4-momentum of L and M
+ JOLD=JPAR
+ IF (SWAP) THEN
+ PPAR(1,LPAR)=-PPAR(1,LPAR)
+ PPAR(1,MPAR)=-PPAR(1,MPAR)
+ JPAR=MPAR
+ ELSE
+ JPAR=LPAR
+ ENDIF
+ PPAR(2,LPAR)=0.
+ CALL HWUROB(RMAT,PPAR(1,LPAR),PPAR(1,LPAR))
+ PPAR(2,MPAR)=0.
+ CALL HWUROB(RMAT,PPAR(1,MPAR),PPAR(1,MPAR))
+C Assign production vertex to L and M
+ CALL HWUDKL(IDPAR(JOLD),PPAR(1,JOLD),VPAR(1,LPAR))
+ CALL HWVSUM(4,VPAR(1,JOLD),VPAR(1,LPAR),VPAR(1,LPAR))
+ CALL HWVEQU(4,VPAR(1,LPAR),VPAR(1,MPAR))
+ ENDIF
+ 60 IF (JDAPAR(1,JPAR).NE.0) GOTO 10
+C Assign decay matrix
+ CALL HWVZRO(2,DECPAR(1,JPAR))
+C Backtrack down the leader
+ 70 IPAR=JMOPAR(1,JPAR)
+ KPAR=JDAPAR(1,IPAR)
+ IF (KPAR.EQ.JPAR) THEN
+C Develop the side branch
+ JPAR=JDAPAR(2,IPAR)
+ GOTO 60
+ ELSE
+C Construct decay matrix
+ CALL HWBAZF(IPAR,KPAR,DECPAR(1,JPAR),DECPAR(1,KPAR),
+ & PHIPAR(1,IPAR),DECPAR(1,IPAR))
+ ENDIF
+ IF (IPAR.EQ.INITBR) RETURN
+ JPAR=IPAR
+ GOTO 70
+ 999 END
+CDECK ID>, HWBTOP.
+*CMZ :- -14/10/99 18.04.56 by Mike Seymour
+*-- Author : Gennaro Corcella
+C-----------------------------------------------------------------------
+ SUBROUTINE HWBTOP
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWBVMC,HWR,HWUALF,HWUSQR,X(3),W,
+ & X3MIN,X3MAX,X1MIN,X1MAX,QSCALE,GLUFAC,R(3,3),M(3),
+ & E(3),AW,PTSQ,EM,EPS,MASDEP,A,B,C,GAMDEP,LAMBDA,
+ & PW(5),PT(5),PW1(5),CS,SN,EPG,QQ,RR,CC
+ INTEGER ID,ID3,IHEP,KHEP,WHEP,ICMF,K
+ EXTERNAL HWBVMC,HWUALF,HWUSQR,HWR
+ LAMBDA(A,B,C)=(A**2+B**2+C**2-2*A*B-2*B*C-2*C*A)/(4*A)
+C---FIND AN UNTREATED CMF
+ ICMF=0
+ DO 10 IHEP=1,NHEP
+C----FIND A DECAYING TOP QUARK
+ 10 IF (ISTHEP(IHEP).EQ.155.AND.ISTHEP(JDAHEP(1,IHEP)).EQ.113
+ & .AND.(IDHW(IHEP).EQ.6.OR.IDHW(IHEP).EQ.12))
+ & ICMF=IHEP
+ IF (ICMF.EQ.0) RETURN
+ EM=PHEP(5,ICMF)
+ X3MIN=2*GCUTME/EM
+C---GENERATE X(1),X(3) ACCORDING TO 1/((1-X(1))*X(3)**2)
+ 100 CONTINUE
+C-----AW=(MW/MT)**2
+ AW=(PHEP(5,JDAHEP(1,ICMF))/EM)**2
+C---CHOOSE X3
+ X3MAX=1-AW
+ X(3)=X3MIN*X3MAX/(X3MIN+(X3MAX-X3MIN)*HWR())
+C--CC, QQ AND RR ARE THE VARIABLE DEFINED IN OUR PAPER
+C--IN ORDER TO SOLVE THE CUBIC EQUATION
+ CC=(1-AW)**2/4
+ QQ=(AW**2-4*(1-X(3))*(2-CC-X(3))-2*AW*(3+2*X(3)))/3
+ & -((3+2*AW-4*X(3))**2)/9
+ RR=((3+2*AW-4*X(3))*(AW**2-4*(1-X(3))*(2-CC-X(3))
+ & -2*AW*(3+2*X(3)))-3*(AW*(4-AW)*(2-CC)+(1-CC)
+ & *(2*(1-X(3))-AW)**2))/6-(ONE/27)*(3+2*AW-4*X(3))**3
+C---CHOOSE X1
+ X1MAX=2*(-QQ**3)**(ONE/6)*COS(ACOS(RR/SQRT(-QQ**3))/3)
+ & -(3+2*AW-4*X(3))/3
+ X1MIN=1-X(3)+(AW*X(3))/(1-X(3))
+ IF (X1MAX.GE.1.OR.X1MIN.GE.1.OR.X1MAX.LE.X1MIN) GOTO 100
+ X(1)=1-(1-X1MAX)*((1-X1MIN)/(1-X1MAX))**HWR()
+C---CALCULATE WEIGHT
+ W=((1+1/AW-2*AW)*((1-AW)*X(3)-(1-X(1))*(1-X(3))-X(3)**2)
+ & +(1+1/(2*AW))*X(3)*(X(1)+X(3)-1)**2+2*X(3)**2*(1-X(1)))
+ & *(1/X3MIN-1/X3MAX)*LOG((1-X1MIN)/(1-X1MAX))
+C---QSCALE=DURHAM-LIKE TRANSVERSE MOMENTUM OF THE GLUON
+ QSCALE=EM*HWUSQR(X(3)*(1-X(1))/(2-X(1)-X(3)-AW))
+C---FACTOR FOR GLUON EMISSION
+ ID=IDHW(JDAHEP(2,ICMF))
+ GLUFAC=0
+ IF (QSCALE.GT.HWBVMC(13)) GLUFAC=CFFAC*HWUALF(1,QSCALE)
+ & /(PIFAC*(1-AW)*(1-2*AW+1/AW))
+C---IN FRACTION GLUFAC*W OF EVENTS ADD A GLUON
+ IF (GLUFAC*W.GT.HWR()) THEN
+ ID3=13
+ ELSE
+ RETURN
+ ENDIF
+C---CHECK INFRA-RED CUT-OFF FOR GLUON
+ M(1)=PHEP(5,JDAHEP(1,ICMF))
+ M(2)=HWBVMC(ID)
+ M(3)=HWBVMC(ID3)
+ E(1)=HALF*EM*(X(1)+AW+(-M(2)**2-M(3)**2)/EM**2)
+ E(3)=HALF*EM*X(3)
+ E(2)=EM-E(1)-E(3)
+ PTSQ=-LAMBDA(E(1)**2-M(1)**2,E(3)**2-M(3)**2,
+ & E(2)**2-M(2)**2)
+ IF (PTSQ.LE.0.OR.E(1).LE.M(1).OR.E(2).LE.M(2).OR.E(3).LE.M(3))
+ $ RETURN
+C---CALCULATE MASS-DEPENDENT SUPPRESSION
+ EPS=(RMASS(ID)/EM)**2
+ EPG=(RMASS(ID3)/EM)**2
+ GAMDEP=(1-AW)*(1+1/AW-2*AW)/(SQRT(1+AW**2+EPS**2
+ & -2*AW-2*EPS-2*AW*EPS)*(1+EPS+(1-EPS)**2/AW-2*AW))
+ MASDEP=GAMDEP/(1-X(1))*((1+EPS+(1-EPS)**2/AW-2*AW)
+ & *((1-AW+EPS)*X(3)*(1-X(1))-(1-X(1))**2*(1-X(3))
+ & -X(3)**2*(1-X(1)+EPS))+(1+(1+EPS)/(2*AW))*X(3)
+ & *(1-X(1))*(X(1)+X(3)-1)**2+2*X(3)**2*(1-X(1))**2)
+ IF (MASDEP.LT.HWR()*((1+1/AW-2*AW)*((1-AW)*X(3)
+ & -(1-X(1))*(1-X(3))-X(3)**2)+(1+1/(2*AW))*X(3)
+ & *(X(1)+X(3)-1)**2+2*X(3)**2*(1-X(1)))) RETURN
+C---STORE OLD MOMENTA
+c---PT = TOP MOMENTUM, PW= W MOMENTUM
+ CALL HWVEQU(5,PHEP(1,ICMF),PT)
+ CALL HWVEQU(5,PHEP(1,JDAHEP(1,ICMF)),PW)
+C--------GET THE NON-EMITTING PARTON CMF DIRECTION
+ CALL HWULOF(PHEP(1,ICMF),PW,PW)
+ CALL HWRAZM(ONE,CS,SN)
+ CALL HWUROT(PW,CS,SN,R)
+ CALL HWUROF(R,PW,PW)
+ CALL HWUMAS(PW)
+C---REORDER ENTRIES: IHEP=EMITTER, KHEP=EMITTED
+ NHEP=NHEP+1
+ IHEP=JDAHEP(2,ICMF)
+ WHEP=JDAHEP(1,ICMF)
+ KHEP=NHEP
+C---SET UP MOMENTA IN TOP REST FRAME
+ PHEP(1,ICMF)=0
+ PHEP(2,ICMF)=0
+ PHEP(3,ICMF)=0
+ PHEP(4,ICMF)=EM
+ PHEP(5,ICMF)=EM
+ PHEP(4,IHEP)=HALF*EM*(2-X(1)-X(3)+EPS-AW+EPG)
+ PHEP(4,KHEP)=HALF*EM*X(3)
+ PHEP(5,IHEP)=RMASS(ID)
+ PHEP(5,KHEP)=RMASS(ID3)
+ PHEP(3,KHEP)=HALF*EM*((X(1)+AW-EPS-EPG)*X(3)-2*(1+EPS-AW
+ $ -EPG-(2+EPS+EPG-AW-X(1)-X(3))))/HWUSQR((X(1)+AW
+ $ -EPS-EPG)**2-4*AW)
+ PHEP(3,IHEP)=-PHEP(3,KHEP)-HALF*EM
+ $ *HWUSQR((X(1)+AW-EPS-EPG)**2-4*AW)
+ PHEP(2,IHEP)=0
+ PHEP(1,KHEP)=HWUSQR(PHEP(4,KHEP)**2-PHEP(5,KHEP)**2
+ $ -PHEP(3,KHEP)**2)
+ PHEP(1,IHEP)=-PHEP(1,KHEP)
+ PHEP(2,KHEP)=0
+ CALL HWVSUM(4,PHEP(1,IHEP),PHEP(1,KHEP),PW1)
+ CALL HWVDIF(4,PHEP(1,ICMF),PW1,PW1)
+ CALL HWUMAS(PW1)
+ DO K=1,5
+ PHEP(K,WHEP)=PW1(K)
+ ENDDO
+C---ORIENT IN CMF, THEN BOOST TO LAB
+ CALL HWUROB(R,PHEP(1,ICMF),PHEP(1,ICMF))
+ CALL HWUROB(R,PHEP(1,IHEP),PHEP(1,IHEP))
+ CALL HWUROB(R,PHEP(1,WHEP),PHEP(1,WHEP))
+ CALL HWUROB(R,PHEP(1,KHEP),PHEP(1,KHEP))
+ CALL HWULOB(PT,PHEP(1,IHEP),PHEP(1,IHEP))
+ CALL HWULOB(PT,PHEP(1,KHEP),PHEP(1,KHEP))
+ CALL HWULOB(PT,PHEP(1,ICMF),PHEP(1,ICMF))
+ CALL HWULOB(PT,PHEP(1,WHEP),PHEP(1,WHEP))
+C---STATUS AND COLOUR CONNECTION
+ ISTHEP(KHEP)=114
+ IDHW(KHEP)=ID3
+ IDHEP(KHEP)=IDPDG(ID3)
+ JDAHEP(2,ICMF)=KHEP
+ JMOHEP(1,KHEP)=ICMF
+ JMOHEP(1,IHEP)=ICMF
+ JDAHEP(1,KHEP)=0
+ JMOHEP(2,IHEP)=ICMF
+ JDAHEP(2,IHEP)=KHEP
+ JMOHEP(2,KHEP)=IHEP
+ JDAHEP(2,KHEP)=ICMF
+ 999 END
+CDECK ID>, HWBVMC.
+*CMZ :- -26/04/91 11.11.54 by Bryan Webber
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ FUNCTION HWBVMC(ID)
+C-----------------------------------------------------------------------
+C VIRTUAL MASS CUTOFF FOR PARTON TYPE ID
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWBVMC
+ INTEGER ID
+ IF (ID.EQ.13) THEN
+ HWBVMC=RMASS(ID)+VGCUT
+ ELSEIF (ID.LT.13) THEN
+ HWBVMC=RMASS(ID)+VQCUT
+ ELSEIF (ID.EQ.59) THEN
+ HWBVMC=RMASS(ID)+VPCUT
+ ELSE
+ HWBVMC=RMASS(ID)
+ ENDIF
+ END
+CDECK ID>, HWCBCT.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ SUBROUTINE HWCBCT(JHEP,KHEP,THEP,PCL,SPLIT)
+C-----------------------------------------------------------------------
+C Subroutine to split a baryonic cluster containing two heavy quarks
+C Based on HWCCUT
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWUPCM,HWR,HWVDOT,EMC,QM1,QM2,QM3,QM4,
+ & PXY,PCX,PCY,RCM,PCL(5),AX(5),PA(5),PB(5),PC(5),
+ & VCLUS(4),DQM,EMX,EMY,SKAPPA,RKAPPA,VTMP(4),
+ & DELTM,PDIQUK(5),AY(5)
+ INTEGER HWRINT,JHEP,KHEP,LHEP,MHEP,THEP,ID1,ID2,ID3,ID4,NTRY,
+ & NTRYMX,J,IB
+ LOGICAL SPLIT
+ EXTERNAL HWUPCM,HWR,HWVDOT
+ PARAMETER(SKAPPA=1.,NTRYMX=100)
+ IF(IERROR.NE.0) RETURN
+ EMC=PCL(5)
+ ID1=IDHW(JHEP)
+ ID2=IDHW(KHEP)
+ ID3=IDHW(THEP)
+ QM1=RMASS(ID1)
+ QM2=RMASS(ID2)
+ QM3=RMASS(ID3)
+ SPLIT = .FALSE.
+ NTRY = 0
+C Decide if cluster contains a b-(anti)quark
+ IF (ID1.EQ.5.OR.ID1.EQ.11.OR.ID2.EQ.5.OR.ID2.EQ.11.OR.
+ & ID3.EQ.5.OR.ID3.EQ.11) THEN
+ IB=2
+ ELSE
+ IB=1
+ ENDIF
+C-- Set the positon of the cluster to be that of the heavy quark
+ CALL HWVEQU(4,VHEP(1,THEP),VCLUS)
+C--SPLIT THE BARYONIC CLUSTER INTO A HEAVY FLAVOUR MESON AND A HEAVY
+C--FLAVOUR BARYON
+ PXY=EMC-QM1-QM2-QM3
+ 20 NTRY=NTRY+1
+ IF(NTRY.GT.NTRYMX) RETURN
+ 30 EMX=QM1+QM2+PXY*HWR()**PSPLT(IB)
+ EMY= QM3+PXY*HWR()**PSPLT(IB)
+ IF(EMX+EMY.GE.EMC) GOTO 30
+C--PULL A LIGHT QUARK PAIR OUT OF THE VACUUM
+ 40 ID4=HWRINT(1,3)
+ IF(QWT(ID4).LT.HWR()) GOTO 40
+ QM4=RMASS(ID4)
+C--Now combine particles 3 & 4 into a diquark
+C--If three also heavy this diquark doesn't exist in HERWIG
+C--just assume mass is sum of quark masses,as for other diquarks
+ DQM=QM3+QM4
+C--Now obtain the masses for the cluster splitting
+ PCX=HWUPCM(EMX,QM1,DQM)
+ IF(PCX.LT.ZERO) GOTO 20
+ PCY=HWUPCM(EMY,QM2,QM4)
+ IF(PCY.LT.ZERO) GOTO 20
+ SPLIT=.TRUE.
+C--Now we've decided which light quark to pull out of the vacuum
+C--Find the direction of the second heavy quark
+ CALL HWULOF(PCL,PHEP(1,THEP),AX)
+ RCM=1./SQRT(HWVDOT(3,AX,AX))
+ CALL HWVSCA(3,RCM,AX,AX)
+C--Construct the new CoM momenta(collinear)
+ PXY=HWUPCM(EMC,EMX,EMY)
+ CALL HWVSCA(3,PXY,AX,PC)
+C--pc is momenta of Y cluster along 2nd quark dirn in cluster frame
+ PC(4)=SQRT(PXY**2+EMY**2)
+ PC(5)=EMY
+C--pa is momenta of 2nd quark in Y frame
+ CALL HWVSCA(3,PCY,AX,PA)
+ PA(4)=SQRT(PCY**2+QM3**2)
+ PA(5)=QM3
+C--pb is momenta of 2nd quark in cluster frame,pa now momenta of antiquark
+ CALL HWULOB(PC,PA,PB)
+ CALL HWVDIF(4,PC,PB,PA)
+ PA(5)=QM4
+ LHEP=NHEP+1
+ MHEP=NHEP+2
+C--boost these momenta back to lab frame
+ CALL HWULOB(PCL,PB,PHEP(1,THEP))
+ CALL HWULOB(PCL,PA,PHEP(1,MHEP))
+C--pc now becomes momenta of X cluster in cluster frame
+ CALL HWVSCA(3,-ONE,PC,PC)
+ PC(4)=EMC-PC(4)
+ PC(5)=EMX
+C--find the dirn of the 1st heavy quark in the X frame
+C--transform to cluster frame
+ CALL HWULOF(PCL,PHEP(1,JHEP),AY)
+C--transform to X-frame
+ CALL HWULOF(PC,AY,AY)
+ RCM=1./SQRT(HWVDOT(3,AY,AY))
+ CALL HWVSCA(3,RCM,AY,AY)
+C--pa now momenta of 1st havy quark along this dirn
+ CALL HWVSCA(3,PCX,AY,PA)
+ PA(4)=SQRT(PCX**2+QM1**2)
+ PA(5)=QM1
+C--pb now momenta of 1st heavy quark in cluster frame then to lab
+ CALL HWULOB(PC,PA,PB)
+ CALL HWULOB(PCL,PB,PHEP(1,JHEP))
+C--now find the diquark momenta by momentum conservation
+ DO 50 J=1,4
+ 50 PDIQUK(J)=PCL(J)-PHEP(J,THEP)-PHEP(J,MHEP)-PHEP(J,JHEP)
+ PDIQUK(5)=DQM
+C--Now obtain the quark momenta from the diquark
+ DO 60 J=1,3
+ 60 PA(J) = 0
+ PA(4) = QM2
+ PA(5) = QM2
+ CALL HWULOB(PDIQUK,PA,PHEP(1,KHEP))
+ CALL HWVDIF(4,PDIQUK,PHEP(1,KHEP),PHEP(1,LHEP))
+C--Construct new vertex positions
+ RKAPPA=GEV2MM/SKAPPA
+ CALL HWVSCA(3,RKAPPA,AX,AX)
+ DELTM=(EMX-EMY)*(EMX+EMY)/(TWO*EMC)
+ CALL HWVSCA(3,DELTM,AX,VTMP)
+ VTMP(4)=(HALF*EMC-PXY)*RKAPPA
+ CALL HWULB4(PCL,VTMP,VTMP)
+ CALL HWVSUM(4,VTMP,VCLUS,VHEP(1,LHEP))
+ CALL HWVEQU(4,VHEP(1,LHEP),VHEP(1,MHEP))
+C--Relabel the colours of the quarks
+ IDHEP(LHEP) = IDPDG(ID4)
+ IDHEP(MHEP) = IDPDG(ID4)
+ IF(IDHEP(JHEP).GT.0) THEN
+ IDHW(LHEP) = ID4+6
+ IDHEP(LHEP) = -IDHEP(LHEP)
+ IDHW(MHEP) = ID4
+ JDAHEP(2,LHEP) = JHEP
+ JMOHEP(2,LHEP) = MHEP
+ JMOHEP(2,MHEP) = JMOHEP(2,JHEP)
+ JDAHEP(2,MHEP) = LHEP
+ JMOHEP(2,JHEP) = LHEP
+ ELSE
+ IDHW(LHEP) = ID4
+ IDHW(MHEP) = ID4+6
+ IDHEP(MHEP) = -IDHEP(MHEP)
+ JMOHEP(2,LHEP) = JHEP
+ JDAHEP(2,MHEP) = JDAHEP(2,JHEP)
+ JDAHEP(2,LHEP) = MHEP
+ JMOHEP(2,MHEP) = LHEP
+ JDAHEP(2,JHEP) = LHEP
+ ENDIF
+ ISTHEP(LHEP) = 151
+ ISTHEP(MHEP) = 151
+ JMOHEP(1,LHEP) = JMOHEP(1,KHEP)
+ JDAHEP(1,LHEP) = 0
+ JMOHEP(1,MHEP) = JMOHEP(1,JHEP)
+ JDAHEP(1,MHEP) = 0
+ NHEP = NHEP+2
+ 999 END
+CDECK ID>, HWCBVI.
+*CMZ :-
+*-- Author : Mark Gibbs modified by Peter Richardson
+C-----------------------------------------------------------------------
+ SUBROUTINE HWCBVI
+C-----------------------------------------------------------------------
+C FINDS UNPAIRED PARTONS AFTER BARYON-NUMBER VIOLATION
+C MODIFIED FOR RPARITY VIOLATING SUSY
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ COMMON/HWBVIC/NBV,IBV(18)
+ DOUBLE PRECISION HWR,PDQ(5)
+ INTEGER NBV,IBV,JBV,KBV,LBV,IHEP,IP1,IP2,IP3,JP1,JP2,JP3,
+ & HWCBVT,NBR,MBV,IQ1,IQ2,IQ3,ID1,ID2,IDQ,IDIQK(3,3)
+ LOGICAL SPLIT,DUNBV(18)
+ DATA IDIQK/111,110,113,110,109,112,113,112,114/
+C---Check for errors
+ IF (IERROR.NE.0) RETURN
+C---Correct colour connections are gluon splitting
+ CALL HWCCCC
+C---Reset bvi clustering flag
+ HVFCEN = .FALSE.
+C---LIST PARTONS WITH WRONG COLOUR PARTNERS-QUARKS ONLY
+ 5 NBV=0
+ DO 10 IHEP=1,NHEP
+ IF (ISTHEP(IHEP).GT.149.AND.ISTHEP(IHEP).LT.155) THEN
+ IF (QORQQB(IDHW(IHEP))) THEN
+ IF (.NOT.QORQQB(IDHW(JMOHEP(2,IHEP))).
+ & AND.JMOHEP(2,IHEP).GT.6) GOTO 10
+ ELSE
+C---Extra check for Gamma's
+ IF (IDHW(IHEP).EQ.59) GO TO 10
+C---End of bug fix.
+ IF (QORQQB(IDHW(JDAHEP(2,IHEP)))) GO TO 10
+ GO TO 10
+ ENDIF
+ IF(JMOHEP(2,IHEP).LT.6.AND.
+ & .NOT.QBORQQ(IDHW(JMOHEP(2,IHEP)))) GOTO 10
+C--new for hard process
+ NBV=NBV+1
+ IF (NBV.GT.18) CALL HWWARN('HWCBVI',100,*999)
+ IBV(NBV)=IHEP
+ DUNBV(NBV)=.FALSE.
+ ENDIF
+ 10 CONTINUE
+C--NOW FIND THE ANTIQUARKS WITH WRONG COLOUR CONNECTIONS
+ DO 11 IHEP=1,NHEP
+ IF(ISTHEP(IHEP).GT.149.AND.ISTHEP(IHEP).LT.155) THEN
+ IF(QBORQQ(IDHW(IHEP))) THEN
+ IF(.NOT.QBORQQ(IDHW(JDAHEP(2,IHEP))).AND.
+ & JDAHEP(2,IHEP).GT.6) GO TO 11
+ ELSE
+C--Extra check for gamma's
+ IF(IDHW(IHEP).EQ.59) GO TO 11
+ IF(QBORQQ(IDHW(JMOHEP(2,IHEP)))) GO TO 11
+ GO TO 11
+ ENDIF
+ IF(JDAHEP(2,IHEP).LT.6.AND.
+ & .NOT.QORQQB(IDHW(JDAHEP(2,IHEP)))) GOTO 11
+ NBV=NBV+1
+ IF(NBV.GT.18) CALL HWWARN('HWCBVI',100,*999)
+ IBV(NBV)=IHEP
+ DUNBV(NBV)=.FALSE.
+ ENDIF
+ 11 CONTINUE
+ IF (NBV.EQ.0) RETURN
+ IF(MOD(NBV,3).NE.0) CALL HWWARN('HWCBVI',101,*999)
+C---PROCESS FOUND PARTONS, STARTING AT RANDOM POINT IN LIST
+ NBR=NBV*HWR()
+ DO 100 MBV=1,NBV
+ JBV=MBV+NBR
+ IF (JBV.GT.NBV) JBV=JBV-NBV
+ IF (.NOT.DUNBV(JBV)) THEN
+ DUNBV(JBV)=.TRUE.
+ IP1=IBV(JBV)
+ JP1=HWCBVT(IP1)
+C---FIND ASSOCIATED PARTONS
+ DO 20 KBV=1,NBV
+ IF (.NOT.DUNBV(KBV)) THEN
+ IP2=IBV(KBV)
+ JP2=HWCBVT(IP2)
+ IF (JP2.EQ.JP1) THEN
+ DUNBV(KBV)=.TRUE.
+ DO 15 LBV=1,NBV
+ IF (.NOT.DUNBV(LBV)) THEN
+ IP3=IBV(LBV)
+ JP3=HWCBVT(IP3)
+ IF (JP3.EQ.JP2) THEN
+ DUNBV(LBV)=.TRUE.
+ GO TO 25
+ ENDIF
+ ENDIF
+ 15 CONTINUE
+ ENDIF
+ ENDIF
+ 20 CONTINUE
+ CALL HWWARN('HWCBVI',102,*999)
+ 25 IQ1=0
+C---LOOK FOR DIQUARK
+ IF (ABS(IDHEP(IP1)).GT.100) THEN
+ IQ1=IP1
+ IQ2=IP2
+ IQ3=IP3
+ ELSEIF (ABS(IDHEP(IP2)).GT.100) THEN
+ IQ1=IP2
+ IQ2=IP3
+ IQ3=IP1
+ ELSEIF (ABS(IDHEP(IP3)).GT.100) THEN
+ IQ1=IP3
+ IQ2=IP1
+ IQ3=IP2
+ ENDIF
+ IF (IQ1.EQ.0) THEN
+C---NO DIQUARKS: COMBINE TWO (ANTI)QUARKS
+ IF (ABS(IDHEP(IP1)).GT.3) THEN
+ IQ1=IP2
+ IQ2=IP3
+ IQ3=IP1
+ ELSEIF (ABS(IDHEP(IP2)).GT.3) THEN
+ IQ1=IP3
+ IQ2=IP1
+ IQ3=IP2
+ ELSE
+ IQ1=IP1
+ IQ2=IP2
+ IQ3=IP3
+ ENDIF
+ ID1=IDHEP(IQ1)
+ ID2=IDHEP(IQ2)
+C---CHECK FLAVOURS
+ IF (ID1.GT.0.AND.ID1.LT.4.AND.
+ & ID2.GT.0.AND.ID2.LT.4) THEN
+ IDQ=IDIQK(ID1,ID2)
+ ELSEIF (ID1.LT.0.AND.ID1.GT.-4.AND.
+ & ID1.LT.0.AND.ID2.GT.-4) THEN
+ IDQ=IDIQK(-ID1,-ID2)+6
+ ELSE
+C---CANT MAKE DIQUARKS WITH HEAVY QUARKS: TRY CLUSTER SPLITTING
+ CALL HWVSUM(4,PHEP(1,IQ1),PHEP(1,IQ2),PDQ)
+ CALL HWUMAS(PDQ)
+C--Use the original splitting procedure
+ CALL HWCCUT(IQ1,IQ2,PDQ,.FALSE.,SPLIT)
+ IF(SPLIT) GOTO 5
+C--If it fails try the new procedure
+ CALL HWVSUM(4,PDQ,PHEP(1,IQ3),PDQ)
+ CALL HWUMAS(PDQ)
+ IF(ABS(ID1).GT.3) THEN
+ CALL HWCBCT(IQ3,IQ2,IQ1,PDQ,SPLIT)
+ ELSEIF(ABS(ID2).GT.3) THEN
+ CALL HWCBCT(IQ3,IQ1,IQ2,PDQ,SPLIT)
+ ELSE
+ CALL HWWARN('HWCBVI',100,*999)
+ ENDIF
+ IF (SPLIT) GO TO 5
+C---Unable to form cluster; dispose of event
+ CALL HWWARN('HWCBVI',-3,*999)
+ ENDIF
+C---OVERWRITE FIRST AND CANCEL SECOND
+ IDHW(IQ1)=IDQ
+ IDHEP(IQ1)=IDPDG(IDQ)
+ CALL HWVSUM(4,PHEP(1,IQ1),PHEP(1,IQ2),PHEP(1,IQ1))
+ CALL HWUMAS(PHEP(1,IQ1))
+ ISTHEP(IQ2)=0
+C---REMAKE COLOUR CONNECTIONS
+ IF (QORQQB(IDQ)) THEN
+ JMOHEP(2,IQ1)=IQ3
+ JDAHEP(2,IQ3)=IQ1
+ ELSE
+ JDAHEP(2,IQ1)=IQ3
+ JMOHEP(2,IQ3)=IQ1
+ ENDIF
+ ELSE
+C---SPLIT A DIQUARK
+ NHEP=NHEP+1
+ CALL HWVSCA(5,HALF,PHEP(1,IQ1),PHEP(1,IQ1))
+ CALL HWVEQU(5,PHEP(1,IQ1),PHEP(1,NHEP))
+ ISTHEP(NHEP)=150
+ JMOHEP(1,NHEP)=JMOHEP(1,IQ1)
+ JDAHEP(1,NHEP)=0
+C---FIND FLAVOURS
+ IDQ=IDHW(IQ1)
+ DO 30 ID2=1,3
+ DO 30 ID1=1,3
+ IF (IDIQK(ID1,ID2).EQ.IDQ) THEN
+ IDHW(IQ1)=ID1
+ IDHW(NHEP)=ID2
+C---REMAKE COLOUR CONNECTIONS (DIQUARK)
+ JMOHEP(2,IQ1)=IQ2
+ JMOHEP(2,IQ2)=NHEP
+ JMOHEP(2,IQ3)=IQ1
+ JMOHEP(2,NHEP)=IQ3
+ JDAHEP(2,IQ1)=IQ3
+ JDAHEP(2,IQ2)=IQ1
+ JDAHEP(2,IQ3)=NHEP
+ JDAHEP(2,NHEP)=IQ2
+ GO TO 35
+ ELSEIF (IDIQK(ID1,ID2).EQ.IDQ-6) THEN
+ IDHW(IQ1)=ID1+6
+ IDHW(NHEP)=ID2+6
+C---REMAKE COLOUR CONNECTIONS (ANTIDIQUARK)
+ JMOHEP(2,IQ1)=IQ3
+ JMOHEP(2,IQ2)=IQ1
+ JMOHEP(2,IQ3)=NHEP
+ JMOHEP(2,NHEP)=IQ2
+ JDAHEP(2,IQ1)=IQ2
+ JDAHEP(2,IQ2)=NHEP
+ JDAHEP(2,IQ3)=IQ1
+ JDAHEP(2,NHEP)=IQ3
+ GO TO 35
+ ENDIF
+ 30 CONTINUE
+ CALL HWWARN('HWCBVI',104,*999)
+ 35 IDHEP(IQ1)=IDPDG(IDHW(IQ1))
+ IDHEP(NHEP)=IDPDG(IDHW(NHEP))
+ ENDIF
+ ENDIF
+ 100 CONTINUE
+ RETURN
+ 999 END
+CDECK ID>, HWCBVT.
+*CMZ :-
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ FUNCTION HWCBVT(IP)
+C-----------------------------------------------------------------------
+C Function to find the baryon number violating vertex a parton came from
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER HWCBVT,IP,JP(2),KP,I,J,ID,TYPE,IDM,IDM2,IDM3,IDM4
+ JP(1) = IP
+ ID = IDHW(IP)
+ IF(ID.LE.6.OR.(ID.GE.115.AND.ID.LE.120)) THEN
+ JP(2) = JMOHEP(2,IP)
+ ELSE
+ JP(2) = JDAHEP(2,IP)
+ ENDIF
+ DO I=1,2
+ IDM = JMOHEP(1,JMOHEP(1,JMOHEP(1,JMOHEP(1,JP(I)))))
+ IF(IDHW(IDM).EQ.6.OR.IDHW(IDM).EQ.12) THEN
+ JP(I)=IDM
+ ENDIF
+ ENDDO
+ DO J=1,7
+ DO I=1,2
+ KP = JMOHEP(1,JP(I))
+ IDM = IDHW(KP)
+ IDM2 = IDHW(JDAHEP(1,KP))
+ IDM3 = IDHW(JDAHEP(2,KP))
+ IDM4 = IDHW(JDAHEP(1,KP)+1)
+ IF((ISTHEP(KP).EQ.155.AND.
+ & ((IDM.GE.449.AND.IDM.LE.457.AND.IDM2.LE.12.AND.
+ & IDM3.LE.12.AND.IDM4.LE.12).OR.
+ & (((IDM.GE.411.AND.IDM.LE.424).OR.IDM.EQ.405.OR.IDM.EQ.406)
+ & .AND.IDM2.LE.12.AND.IDM3.LE.12)))
+ & .OR.(IDM.EQ.15.AND.IDM2.LE.12.AND.
+ & IDHW(JMOHEP(1,KP)).LE.12.AND.
+ & IDHW(JMOHEP(2,KP)).LE.12.AND.IDM3.GE.449.AND.
+ & IDM3.LE.457).OR.
+ & (IDM.EQ.15.AND.IDM2.GE.198.AND.IDM2.LE.200.
+ & AND.ABS(IDPDG(IDM3)).GT.1000000)) THEN
+ IF(IDHW(KP).EQ.449.AND.JDAHEP(1,KP).EQ.JP(I)) THEN
+ KP = JMOHEP(1,KP)
+ ELSEIF(IDHW(KP).EQ.15) THEN
+ TYPE=IDHW(JDAHEP(1,KP))
+ IF(TYPE.GE.7.AND.TYPE.LE.12.AND.
+ & JMOHEP(2,JDAHEP(2,KP)).EQ.JP(I)) THEN
+ KP=IP
+ ELSEIF(TYPE.LE.6.AND.
+ & JDAHEP(2,JDAHEP(2,KP)).EQ.JP(I)) THEN
+ KP=IP
+ ELSE
+ HWCBVT = KP
+ RETURN
+ ENDIF
+ ELSE
+ HWCBVT = KP
+ RETURN
+ ENDIF
+ ENDIF
+ JP(I) =KP
+ ENDDO
+ ENDDO
+ HWCBVT = 0
+ 999 END
+CDECK ID>, HWCCCC.
+*CMZ :-
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ SUBROUTINE HWCCCC
+C-----------------------------------------------------------------------
+C Subroutine to correct colour connections after the gluon splitting
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER IHEP,STFSPT,LHEP,MHEP,RHEP
+ IF(IERROR.NE.0) RETURN
+C--Find the first particle in the event record with status 150
+ DO IHEP=1,NHEP
+ IF(ISTHEP(IHEP).GE.150.AND.ISTHEP(IHEP).LE.154) THEN
+ STFSPT = IHEP
+ GOTO 10
+ ENDIF
+ ENDDO
+ 10 CONTINUE
+C--Now find any that are colour connected to earlier particles
+C--in the event record
+ DO IHEP=STFSPT,NHEP
+C--First the quarks and antidiquarks
+ IF(IDHW(IHEP).LT.6.OR.
+ & (IDHW(IHEP).GE.115.AND.IDHW(IHEP).LE.120)) THEN
+ IF(JMOHEP(2,IHEP).LT.STFSPT) THEN
+ LHEP = IHEP
+ MHEP = JMOHEP(2,IHEP)
+ RHEP = MHEP
+ IF(MHEP.GT.6) RHEP = JDAHEP(1,MHEP)
+C--As from Rparity connect to particle not to antiparticle
+ IF(IDHW(MHEP).NE.13) THEN
+ JMOHEP(2,LHEP) = RHEP
+ ELSE
+ RHEP = RHEP+1
+ JMOHEP(2,LHEP) = RHEP
+ ENDIF
+ ENDIF
+ ENDIF
+C--Now the antiquarks
+ IF((IDHW(IHEP).GT.6.AND.IDHW(IHEP).LE.12).OR.
+ & (IDHW(IHEP).GE.109.AND.IDHW(IHEP).LE.114)) THEN
+ IF(JDAHEP(2,IHEP).LT.STFSPT) THEN
+ LHEP = IHEP
+ MHEP = JDAHEP(2,IHEP)
+ RHEP = MHEP
+ IF(MHEP.GT.6) RHEP = JDAHEP(1,MHEP)
+C--As from Rparity connect to antiparticle not particle
+ IF(IDHW(MHEP).NE.13) THEN
+ JDAHEP(2,LHEP) = RHEP
+ ELSE
+ JDAHEP(2,LHEP) = RHEP
+ ENDIF
+ ENDIF
+ ENDIF
+ ENDDO
+ END
+CDECK ID>, HWCCUT.
+*CMZ :- -26/04/91 14.29.39 by Federico Carminati
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWCCUT(JHEP,KHEP,PCL,BTCLUS,SPLIT)
+C-----------------------------------------------------------------------
+C Cuts into 2 the cluster, momentum PCL, made of partons JHEP & KHEP
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWREXQ,HWUPCM,HWR,HWVDOT,EMC,QM1,QM2,EMX,EMY,
+ & QM3,PXY,PCX,PCY,RCM,PCL(5),AX(5),PA(5),PB(5),PC(5),SKAPPA,DELTM,
+ & VSCA,VTMP(4),RKAPPA,VCLUS
+ INTEGER HWRINT,JHEP,KHEP,LHEP,MHEP,ID1,ID2,ID3,NTRY,NTRYMX,J,IB
+ LOGICAL BTCLUS,SPLIT
+ EXTERNAL HWREXQ,HWUPCM,HWR,HWVDOT,HWRINT
+ COMMON/HWCFRM/VCLUS(4,NMXHEP)
+ PARAMETER (SKAPPA=1.,NTRYMX=100)
+ IF (IERROR.NE.0) RETURN
+ EMC=PCL(5)
+ ID1=IDHW(JHEP)
+ ID2=IDHW(KHEP)
+ QM1=RMASS(ID1)
+ QM2=RMASS(ID2)
+ SPLIT=.FALSE.
+ NTRY=0
+C Decide if cluster contains a b-(anti)quark
+ IF (ID1.EQ.5.OR.ID1.EQ.11.OR.ID2.EQ.5.OR.ID2.EQ.11) THEN
+ IB=2
+ ELSE
+ IB=1
+ ENDIF
+ IF (BTCLUS) THEN
+C Split beam and target clusters as soft clusters
+C Both (remnant) children treated like soft clusters if IOPREM=0(1)
+ 10 ID3=HWRINT(1,2)
+ QM3=RMASS(ID3)
+ IF (EMC.LE.QM1+QM2+2.*QM3) THEN
+ ID3=3-ID3
+ QM3=RMASS(ID3)
+ IF (EMC.LE.QM1+QM2+2.*QM3) RETURN
+ ENDIF
+ PXY=EMC-QM1-QM2-TWO*QM3
+ IF (ISTHEP(JHEP).EQ.153.OR.ISTHEP(JHEP).EQ.154.OR.
+ & IOPREM.EQ.0) THEN
+ EMX=QM1+QM3+HWREXQ(BTCLM,PXY)
+ ELSE
+ EMX=QM1+QM3+PXY*HWR()**PSPLT(IB)
+ ENDIF
+ IF (ISTHEP(KHEP).EQ.153.OR.ISTHEP(KHEP).EQ.154.OR.
+ & IOPREM.EQ.0) THEN
+ EMY=QM2+QM3+HWREXQ(BTCLM,PXY)
+ ELSE
+ EMY=QM2+QM3+PXY*HWR()**PSPLT(IB)
+ ENDIF
+ IF (EMX+EMY.GE.EMC) THEN
+ NTRY=NTRY+1
+ IF (NTRY.GT.NTRYMX) RETURN
+ GOTO 10
+ ENDIF
+ PCX=HWUPCM(EMX,QM1,QM3)
+ PCY=HWUPCM(EMY,QM2,QM3)
+ ELSE
+C Choose fragment masses for ordinary cluster
+ PXY=EMC-QM1-QM2
+ 20 NTRY=NTRY+1
+ IF (NTRY.GT.NTRYMX) RETURN
+ 30 EMX=QM1+PXY*HWR()**PSPLT(IB)
+ EMY=QM2+PXY*HWR()**PSPLT(IB)
+ IF (EMX+EMY.GE.EMC) GOTO 30
+C u,d,s pair production with weights QWT
+ 40 ID3=HWRINT(1,3)
+ IF (QWT(ID3).LT.HWR()) GOTO 40
+ QM3=RMASS(ID3)
+ PCX=HWUPCM(EMX,QM1,QM3)
+ IF (PCX.LT.ZERO) GOTO 20
+ PCY=HWUPCM(EMY,QM2,QM3)
+ IF (PCY.LT.ZERO) GOTO 20
+ SPLIT=.TRUE.
+ ENDIF
+C Boost antiquark to CoM frame to find axis
+ CALL HWULOF(PCL,PHEP(1,KHEP),AX)
+ RCM=1./SQRT(HWVDOT(3,AX,AX))
+ CALL HWVSCA(3,RCM,AX,AX)
+C Construct new CoM momenta (collinear)
+ PXY=HWUPCM(EMC,EMX,EMY)
+ CALL HWVSCA(3,PXY,AX,PC)
+ PC(4)=SQRT(PXY**2+EMY**2)
+ PC(5)=EMY
+ CALL HWVSCA(3,PCY,AX,PA)
+ PA(4)=SQRT(PCY**2+QM2**2)
+ PA(5)=QM2
+ CALL HWULOB(PC,PA,PB)
+ CALL HWVDIF(4,PC,PB,PA)
+ PA(5)=QM3
+ LHEP=NHEP+1
+ MHEP=NHEP+2
+ CALL HWULOB(PCL,PB,PHEP(1,KHEP))
+ CALL HWULOB(PCL,PA,PHEP(1,MHEP))
+ CALL HWVSCA(3,-ONE,PC,PC)
+ PC(4)=EMC-PC(4)
+ PC(5)=EMX
+ CALL HWVSCA(3,PCX,AX,PA)
+ PA(4)=SQRT(PCX**2+QM3**2)
+ CALL HWULOB(PC,PA,PB)
+ CALL HWULOB(PCL,PB,PHEP(1,LHEP))
+ DO 50 J=1,4
+ 50 PHEP(J,JHEP)=PCL(J)-PHEP(J,KHEP)-PHEP(J,LHEP)-PHEP(J,MHEP)
+ PHEP(5,JHEP)=QM1
+ CALL HWVEQU(4,VHEP(1,LHEP),VHEP(1,MHEP))
+C Construct new vertex positions
+ RKAPPA=GEV2MM/SKAPPA
+ CALL HWVSCA(3,RKAPPA,AX,AX)
+ DELTM=(EMX-EMY)*(EMX+EMY)/(TWO*EMC)
+ CALL HWVSCA(3,DELTM,AX,VTMP)
+ VTMP(4)=(HALF*EMC-PXY)*RKAPPA
+ CALL HWULB4(PCL,VTMP,VTMP)
+ CALL HWVSUM(4,VTMP,VCLUS(1,JHEP),VHEP(1,LHEP))
+ CALL HWVEQU(4,VHEP(1,LHEP),VHEP(1,MHEP))
+ VSCA=0.25*EMC+HALF*(PXY+DELTM)
+ CALL HWVSCA(3,VSCA,AX,VTMP)
+ VTMP(4)=(EMC-VSCA)*RKAPPA
+ CALL HWULB4(PCL,VTMP,VTMP)
+ CALL HWVSUM(4,VTMP,VCLUS(1,JHEP),VCLUS(1,MHEP))
+ VSCA=-0.25*EMC+HALF*(DELTM-PXY)
+ CALL HWVSCA(3,VSCA,AX,VTMP)
+ VTMP(4)=(EMC+VSCA)*RKAPPA
+ CALL HWULB4(PCL,VTMP,VTMP)
+ CALL HWVSUM(4,VTMP,VCLUS(1,JHEP),VCLUS(1,JHEP))
+C (Re-)label quarks
+ IDHW(LHEP)=ID3+6
+ IDHW(MHEP)=ID3
+ IDHEP(MHEP)= IDPDG(ID3)
+ IDHEP(LHEP)=-IDPDG(ID3)
+ ISTHEP(LHEP)=151
+ ISTHEP(MHEP)=151
+ JMOHEP(2,JHEP)=LHEP
+ JDAHEP(2,KHEP)=MHEP
+ JMOHEP(1,LHEP)=JMOHEP(1,KHEP)
+ JMOHEP(2,LHEP)=MHEP
+ JDAHEP(1,LHEP)=0
+ JDAHEP(2,LHEP)=JHEP
+ JMOHEP(1,MHEP)=JMOHEP(1,JHEP)
+ JMOHEP(2,MHEP)=KHEP
+ JDAHEP(1,MHEP)=0
+ JDAHEP(2,MHEP)=LHEP
+ NHEP=NHEP+2
+ 999 END
+CDECK ID>, HWCDEC.
+*CMZ :- -26/04/91 10.18.56 by Bryan Webber
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWCDEC
+C-----------------------------------------------------------------------
+C DECAYS CLUSTERS INTO PRIMARY HADRONS
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER JCL,KCL,IP,JP,KP,IST,ID1,ID2,ID3
+ IF (IERROR.NE.0) RETURN
+ IF (IPROC/1000.EQ.9.OR.IPROC/1000.EQ.5) THEN
+C---RELABEL CLUSTER CONNECTED TO REMNANT IN DIS
+ DO 10 JCL=2,NHEP
+ IF (ISTHEP(JCL).EQ.164) GOTO 20
+ IF (ISTHEP(JCL).EQ.165) THEN
+ IP=JMOHEP(1,JCL)
+ JP=JMOHEP(2,JCL)
+ KP=IP
+ IF (ISTHEP(IP).EQ.162) THEN
+ KP=JP
+ JP=IP
+ ENDIF
+ IF (JMOHEP(2,KP).NE.JP) THEN
+ IP=JMOHEP(2,KP)
+ ELSE
+ IP=JDAHEP(2,KP)
+ ENDIF
+ KCL=JDAHEP(1,IP)
+ IF (ISTHEP(KCL)/10.NE.16) CALL HWWARN('HWCDEC',100,*999)
+ ISTHEP(KCL)=164
+ GOTO 20
+ ENDIF
+ 10 CONTINUE
+ ENDIF
+ 20 CONTINUE
+ DO 30 JCL=1,NHEP
+ IST=ISTHEP(JCL)
+ IF (IST.GT.162.AND.IST.LT.166) THEN
+C---DON'T HADRONIZE BEAM/TARGET CLUSTERS
+ IF (IST.EQ.163.OR..NOT.GENSOF) THEN
+C---SET UP FLAVOURS FOR CLUSTER DECAY
+ CALL HWCFLA(IDHW(JMOHEP(1,JCL)),IDHW(JMOHEP(2,JCL)),ID1,ID3)
+ CALL HWCHAD(JCL,ID1,ID3,ID2)
+ ENDIF
+ ENDIF
+ 30 CONTINUE
+ ISTAT=50
+ 999 END
+CDECK ID>, HWCFLA.
+*CMZ :- -26/04/91 10.18.56 by Bryan Webber
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWCFLA(JD1,JD2,ID1,ID2)
+C-----------------------------------------------------------------------
+C SETS UP FLAVOURS FOR CLUSTER DECAY
+C-----------------------------------------------------------------------
+ INTEGER JD1,JD2,ID1,ID2,JD,JDEC(12)
+ DATA JDEC/1,2,3,10,11,12,4,5,6,7,8,9/
+ JD=JD1
+ IF (JD.GT.12) JD=JD-108
+ ID1=JDEC(JD)
+ JD=JD2
+ IF (JD.GT.12) JD=JD-96
+ ID2=JDEC(JD-6)
+ END
+CDECK ID>, HWCFOR.
+*CMZ :- -26/04/91 14.15.56 by Federico Carminati
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWCFOR
+C-----------------------------------------------------------------------
+C Converts colour-connected quark-antiquark pairs into clusters
+C Modified by IGK to include BRW's colour rearrangement and
+C MHS's cluster vertices
+C MODIFIED 16/10/97 BY BRW FOR SUSY PROCESSES
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWULDO,HWVDOT,HWR,HWUPCM,DCL0,DCL(4),DCL1,
+ & DFAC,DISP1(4),DISP2(4),DMAX,PCL(5),DOT1,DOT2,FAC,VCLUS,SCA1,SCA2,
+ & EM0,EM1,EM2,PC0,PC1
+ INTEGER HWRINT,MAP(120),IBHEP,IBCL,JBHEP,JHEP,
+ & KHEP,LHEP,LCL,IHEP,MCL,I,ISTJ,ISTK,JCL,ID1,ID3,L
+ LOGICAL HWRLOG,SPLIT
+ EXTERNAL HWULDO,HWVDOT,HWR,HWUPCM,HWRINT
+ COMMON/HWCFRM/VCLUS(4,NMXHEP)
+ DATA MAP/1,2,3,4,5,6,1,2,3,4,5,6,96*0,7,8,9,10,11,12,7,8,9,10,11,
+ & 12/
+ IF (IERROR.NE.0) RETURN
+C Split gluons
+ CALL HWCGSP
+C Find colour partners after baryon number violating event
+ IF (HVFCEN) THEN
+ IF(RPARTY) THEN
+ CALL HVCBVI
+ ELSE
+ CALL HWCBVI
+ ENDIF
+ ENDIF
+ IF (IERROR.NE.0) RETURN
+C Look for partons to cluster
+ DO 10 IBHEP=1,NHEP
+ 10 IF (ISTHEP(IBHEP).GE.150.AND.ISTHEP(IBHEP).LE.154) GOTO 20
+ IBCL=1
+ GOTO 130
+ 20 CONTINUE
+C--Final check for colour disconnections
+ DO 25 JHEP=IBHEP,NHEP
+ IF (ISTHEP(JHEP).GE.150.AND.ISTHEP(JHEP).LE.154.AND.
+ & QORQQB(IDHW(JHEP))) THEN
+ KHEP=JMOHEP(2,JHEP)
+C BRW FIX 13/03/99
+ IF (KHEP.EQ.0.OR..NOT.(
+ & ISTHEP(KHEP).GE.150.AND.ISTHEP(KHEP).LE.154.AND.
+ & QBORQQ(IDHW(KHEP)))) THEN
+ DO KHEP=IBHEP,NHEP
+ IF (ISTHEP(KHEP).GE.150.AND.ISTHEP(KHEP).LE.154
+ & .AND.QBORQQ(IDHW(KHEP))) THEN
+ LHEP=JDAHEP(2,KHEP)
+ IF (LHEP.EQ.0.OR..NOT.(
+ & ISTHEP(LHEP).GE.150.AND.ISTHEP(LHEP).LE.154.AND.
+ & QORQQB(IDHW(LHEP)))) THEN
+ JMOHEP(2,JHEP)=KHEP
+ JDAHEP(2,KHEP)=JHEP
+ GOTO 25
+ ENDIF
+ ENDIF
+ ENDDO
+C END FIX
+ CALL HWWARN('HWCFOR',100,*999)
+ ENDIF
+ ENDIF
+ 25 CONTINUE
+ IF (CLRECO) THEN
+C Allow for colour rearrangement of primary clusters
+ NRECO=0
+C Randomize starting point
+ JBHEP=HWRINT(IBHEP,NHEP)
+ JHEP=JBHEP
+ 30 JHEP=JHEP+1
+ IF (JHEP.GT.NHEP) JHEP=IBHEP
+ IF (ISTHEP(JHEP).GE.150.AND.ISTHEP(JHEP).LE.154.AND.
+ & QORQQB(IDHW(JHEP))) THEN
+C Find colour connected antiquark or diquark
+ KHEP=JMOHEP(2,JHEP)
+C Find partner antiquark or diquark
+ LHEP=JDAHEP(2,JHEP)
+C Find closest antiquark or diquark
+ DCL0=1.D15
+ LCL=0
+ DO 40 IHEP=IBHEP,NHEP
+ IF (ISTHEP(IHEP).GE.150.AND.ISTHEP(IHEP).LE.154.AND.
+ & QBORQQ(IDHW(IHEP))) THEN
+C Check whether already reconnected
+ IF (JDAHEP(2,IHEP).GT.0.AND.IHEP.NE.LHEP) THEN
+ CALL HWVDIF(4,VHEP(1,IHEP),VHEP(1,JHEP),DCL)
+ DCL1=ABS(HWULDO(DCL,DCL))
+ IF (DCL1.LT.DCL0) THEN
+ DCL0=DCL1
+ LCL=IHEP
+ ENDIF
+ ENDIF
+ ENDIF
+ 40 CONTINUE
+ IF (LCL.NE.0.AND.LCL.NE.KHEP) THEN
+ MCL=JDAHEP(2,LCL)
+ IF (JDAHEP(2,MCL).NE.KHEP) THEN
+C Pairwise reconnection is possible
+ CALL HWVDIF(4,VHEP(1,KHEP),VHEP(1,MCL ),DCL)
+ DCL0=DCL0+ABS(HWULDO(DCL,DCL))
+ CALL HWVDIF(4,VHEP(1,JHEP),VHEP(1,KHEP),DCL)
+ DCL1=ABS(HWULDO(DCL,DCL))
+ CALL HWVDIF(4,VHEP(1,LCL ),VHEP(1,MCL ),DCL)
+ DCL1=DCL1+ABS(HWULDO(DCL,DCL))
+ IF (DCL0.LT.DCL1.AND.HWRLOG(PRECO)) THEN
+C Reconnection occurs
+ JMOHEP(2,JHEP)= LCL
+ JDAHEP(2,LCL )=-JHEP
+ JMOHEP(2,MCL) = KHEP
+ JDAHEP(2,KHEP)=-MCL
+ NRECO=NRECO+1
+ ENDIF
+ ENDIF
+ ENDIF
+ ENDIF
+ IF (JHEP.NE.JBHEP) GOTO 30
+ IF (NRECO.NE.0) THEN
+ DO 50 IHEP=IBHEP,NHEP
+ 50 JDAHEP(2,IHEP)=ABS(JDAHEP(2,IHEP))
+ ENDIF
+ ENDIF
+C Find (adjusted) cluster positions using MHS prescription
+ DFAC=10
+ DMAX=1D-10
+ DO 70 JHEP=IBHEP,NHEP
+ IF (ISTHEP(JHEP).GE.150.AND.ISTHEP(JHEP).LE.154.AND.
+ & QORQQB(IDHW(JHEP))) THEN
+ KHEP=JMOHEP(2,JHEP)
+ CALL HWUDKL(IDHW(JHEP),PHEP(1,JHEP),DISP1)
+ CALL HWVSCA(4,DFAC,DISP1,DISP1)
+ CALL HWUDKL(IDHW(KHEP),PHEP(1,KHEP),DISP2)
+ CALL HWVSCA(4,DFAC,DISP2,DISP2)
+C Rescale the lengths of DISP1,DISP2 if too long
+ DOT1=HWVDOT(3,DISP1,DISP1)
+ DOT2=HWVDOT(3,DISP2,DISP2)
+ IF (MAX(DOT1,DOT2).GT.DMAX**2) THEN
+ CALL HWVSCA(4,DMAX/SQRT(DOT1),DISP1,DISP1)
+ CALL HWVSCA(4,DMAX/SQRT(DOT2),DISP2,DISP2)
+ ENDIF
+ CALL HWVSUM(4,PHEP(1,JHEP),PHEP(1,KHEP),PCL)
+ DOT1=HWVDOT(3,DISP1,PCL)
+ DOT2=HWVDOT(3,DISP2,PCL)
+C If PCL > 90^o from either quark, use a vector which isn't
+ IF (DOT1.LE.ZERO.OR. DOT2.LE.ZERO) THEN
+ CALL HWVSUM(4,DISP1,DISP2,PCL)
+ DOT1=HWVDOT(3,DISP1,PCL)
+ DOT2=HWVDOT(3,DISP2,PCL)
+ ENDIF
+C If vectors are exactly opposite each other this method cannot work
+ IF (DOT1.EQ.ZERO.OR.DOT2.EQ.ZERO) THEN
+C So use midpoint of quark constituents
+ CALL HWVSUM(4,VHEP(1,JHEP),VHEP(1,KHEP),VCLUS(1,JHEP))
+ CALL HWVSCA(4,HALF,VCLUS(1,JHEP),VCLUS(1,JHEP))
+ GOTO 70
+ ENDIF
+C Rescale DISP1 or DISP2 to give equal components in the PCL direction
+ FAC=DOT1/DOT2
+ IF (FAC.GT.ONE) THEN
+ CALL HWVSCA(4, FAC,DISP2,DISP2)
+ DOT2=DOT1
+ ELSE
+ CALL HWVSCA(4,ONE/FAC,DISP1,DISP1)
+ DOT1=DOT2
+ ENDIF
+C Shift VHEP(1,JHEP) or VHEP(1,KHEP) s.t. their line is perp to PCL
+ FAC=(HWVDOT(3,PCL,VHEP(1,KHEP))
+ & -HWVDOT(3,PCL,VHEP(1,JHEP)))/DOT1
+ SCA1=MAX(ONE,ONE+FAC)
+ SCA2=MAX(ONE,ONE-FAC)
+ DO 60 I=1,4
+ 60 VCLUS(I,JHEP)=.5*(VHEP(I,JHEP)+VHEP(I,KHEP)
+ & +SCA1*DISP1(I)+SCA2*DISP2(I))
+ ENDIF
+ 70 CONTINUE
+C First chop up beam/target clusters
+ DO 80 JHEP=IBHEP,NHEP
+ KHEP=JMOHEP(2,JHEP)
+ ISTJ=ISTHEP(JHEP)
+ ISTK=ISTHEP(KHEP)
+C--PR MOD here 8/7/99
+ IF (QORQQB(IDHW(JHEP)).AND.
+ & (((ISTJ.EQ.153.OR.ISTJ.EQ.154).AND.ISTK.NE.151.AND.ISTK.NE.0)
+ & .OR.((ISTK.EQ.153.OR.ISTK.EQ.154).
+ & AND.ISTJ.NE.151.AND.ISTJ.NE.0))) THEN
+C--end
+ CALL HWVSUM(4,PHEP(1,JHEP),PHEP(1,KHEP),PCL)
+ CALL HWUMAS(PCL)
+ CALL HWCCUT(JHEP,KHEP,PCL,.TRUE.,SPLIT)
+ ENDIF
+ 80 CONTINUE
+C Second chop up massive pairs
+ DO 100 JHEP=IBHEP,NMXHEP
+ IF (JHEP.GT.NHEP) GOTO 110
+ IF (ISTHEP(JHEP).GE.150.AND.ISTHEP(JHEP).LE.154.AND.
+ & QORQQB(IDHW(JHEP))) THEN
+ 90 KHEP=JMOHEP(2,JHEP)
+ CALL HWVSUM(4,PHEP(1,JHEP),PHEP(1,KHEP),PCL)
+ CALL HWUMAS(PCL)
+ IF (PCL(5).GT.CTHRPW(MAP(IDHW(JHEP)),MAP(IDHW(KHEP)))) THEN
+ CALL HWCCUT(JHEP,KHEP,PCL,.FALSE.,SPLIT)
+ IF (SPLIT) GOTO 90
+ ENDIF
+ ENDIF
+ 100 CONTINUE
+C Third create clusters and store production vertex
+ 110 IBCL=NHEP+1
+ JCL=NHEP
+ DO 120 JHEP=IBHEP,NHEP
+ IF (ISTHEP(JHEP).GE.150.AND.ISTHEP(JHEP).LE.154.AND.
+ & QORQQB(IDHW(JHEP))) THEN
+ JCL=JCL+1
+ IF(JCL.GT.NMXHEP) CALL HWWARN('HWCFOR',105,*999)
+ IDHW(JCL)=19
+ IDHEP(JCL)=91
+ KHEP=JMOHEP(2,JHEP)
+ IF (KHEP.EQ.0.OR..NOT.(
+ & ISTHEP(KHEP).GE.150.AND.ISTHEP(KHEP).LE.154.AND.
+ & QBORQQ(IDHW(KHEP)))) CALL HWWARN('HWCFOR',104,*999)
+ CALL HWVSUM(4,PHEP(1,JHEP),PHEP(1,KHEP),PHEP(1,JCL))
+ CALL HWUMAS(PHEP(1,JCL))
+ IF (ISTHEP(JHEP).EQ.153.OR.ISTHEP(KHEP).EQ.153) THEN
+ ISTHEP(JCL)=164
+ ELSEIF (ISTHEP(JHEP).EQ.154.OR.ISTHEP(KHEP).EQ.154) THEN
+ ISTHEP(JCL)=165
+ ELSE
+ ISTHEP(JCL)=163
+ ENDIF
+ JMOHEP(1,JCL)=JHEP
+ JMOHEP(2,JCL)=KHEP
+ JDAHEP(1,JCL)=0
+ JDAHEP(2,JCL)=0
+ JDAHEP(1,JHEP)=JCL
+ JDAHEP(1,KHEP)=JCL
+ ISTHEP(JHEP)=ISTHEP(JHEP)+8
+ ISTHEP(KHEP)=ISTHEP(KHEP)+8
+ CALL HWVEQU(4,VCLUS(1,JHEP),VHEP(1,JCL))
+ ENDIF
+ 120 CONTINUE
+ NHEP=JCL
+C Fix up momenta for single-hadron clusters
+ 130 DO 150 JCL=IBCL,NHEP
+C Don't hadronize beam/target clusters
+ IF (ISTHEP(JCL).LT.163.OR.ISTHEP(JCL).GT.165) GOTO 150
+ IF (ISTHEP(JCL).NE.163.AND.GENSOF) GOTO 150
+C Set up flavours for cluster decay
+ CALL HWCFLA(IDHW(JMOHEP(1,JCL)),IDHW(JMOHEP(2,JCL)),ID1,ID3)
+ EM0=PHEP(5,JCL)
+ IF ((B1LIM.EQ.ZERO).OR.(ID1.NE.11.AND.ID3.NE.11)) THEN
+ IF (EM0.GT.RMIN(ID1,2)+RMIN(2,ID3)) GOTO 150
+ ELSE
+C Special for b clusters: allow 1-hadron decay above threshold
+ IF (B1LIM*HWR().LT.EM0/(RMIN(ID1,2)+RMIN(2,ID3))-1.)
+ & GOTO 150
+ ENDIF
+ EM1=RMIN(ID1,ID3)
+ IF (ABS(EM0-EM1).LT.1.D-5) GOTO 150
+C Decide to go backward or forward to transfer 4-momentum
+ L=1-TWO*INT(HALF+HWR())
+ MCL=NHEP-IBCL+1
+ LCL=JCL
+ DO 140 I=1,MCL
+ LCL=LCL+L
+ IF (LCL.LT.IBCL) LCL=LCL+MCL
+ IF (LCL.GT.NHEP) LCL=LCL-MCL
+ IF (LCL.EQ.JCL) THEN
+ IF (EM0.GE.EM1+RMIN(1,1)) GOTO 150
+ CALL HWWARN('HWCFOR',101,*999)
+ ENDIF
+ IF (ISTHEP(LCL).LT.163.OR.ISTHEP(LCL).GT.165) GOTO 140
+C Rescale momenta in 2-cluster CoM
+ CALL HWVSUM(4,PHEP(1,JCL),PHEP(1,LCL),PCL)
+ CALL HWUMAS(PCL)
+ EM2=PHEP(5,LCL)
+ PC0=HWUPCM(PCL(5),EM0,EM2)
+ PC1=HWUPCM(PCL(5),EM1,EM2)
+ IF (PC1.LT.ZERO) THEN
+C Need to rescale other mass as well
+ CALL HWCFLA(IDHW(JMOHEP(1,LCL)),IDHW(JMOHEP(2,LCL)),ID1,ID3)
+ EM2=RMIN(ID1,ID3)
+ PC1=HWUPCM(PCL(5),EM1,EM2)
+ IF (PC1.LT.ZERO) GOTO 140
+ PHEP(5,LCL)=EM2
+ ENDIF
+ IF (PC0.GT.ZERO) THEN
+ PC0=PC1/PC0
+ CALL HWULOF(PCL,PHEP(1,JCL),PHEP(1,JCL))
+ CALL HWVSCA(3,PC0,PHEP(1,JCL),PHEP(1,JCL))
+ PHEP(4,JCL)=SQRT(PC1**2+EM1**2)
+ PHEP(5,JCL)=EM1
+ CALL HWULOB(PCL,PHEP(1,JCL),PHEP(1,JCL))
+ CALL HWVDIF(4,PCL,PHEP(1,JCL),PHEP(1,LCL))
+ GOTO 150
+ ELSEIF (PC0.EQ.ZERO) THEN
+ PHEP(5,JCL)=EM1
+ CALL HWDTWO(PCL,PHEP(1,JCL),PHEP(1,LCL),PC1,TWO,.TRUE.)
+ GOTO 150
+ ELSE
+ CALL HWWARN('HWCFOR',102,*999)
+ ENDIF
+ 140 CONTINUE
+ CALL HWWARN('HWCFOR',103,*999)
+ 150 CONTINUE
+ ISTAT=60
+C Non-partons labelled as partons (ie photons) should get copied
+ DO 160 IHEP=1,NHEP
+ IF (ISTHEP(IHEP).EQ.150) THEN
+ NHEP=NHEP+1
+ JDAHEP(1,IHEP)=NHEP
+ ISTHEP(IHEP)=157
+ ISTHEP(NHEP)=190
+ IDHW(NHEP)=IDHW(IHEP)
+ IDHEP(NHEP)=IDPDG(IDHW(IHEP))
+ CALL HWVEQU(5,PHEP(1,IHEP),PHEP(1,NHEP))
+ CALL HWVEQU(4,VHEP(1,IHEP),VHEP(1,NHEP))
+ JMOHEP(1,NHEP)=IHEP
+ JMOHEP(2,NHEP)=JMOHEP(1,IHEP)
+ JDAHEP(1,NHEP)=0
+ JDAHEP(2,NHEP)=0
+ ENDIF
+ 160 CONTINUE
+ 999 END
+CDECK ID>, HWCGSP.
+*CMZ :- -13/07/92 20.15.54 by Mike Seymour
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWCGSP
+C-----------------------------------------------------------------------
+C SPLITS ANY TIMELIKE GLUONS REMAINING AFTER PERTURBATIVE
+C BRANCHING INTO LIGHT (I.E. U OR D) Q-QBAR PAIRS
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWR,PF
+ INTEGER HWRINT,IHEP,JHEP,KHEP,LHEP,MHEP,ID,J,IST
+ EXTERNAL HWR,HWRINT
+ IF (NGSPL.EQ.0) CALL HWWARN('HWCGSP',400,*999)
+ LHEP=NHEP-1
+ MHEP=NHEP
+ DO 100 IHEP=1,NHEP
+ IF (ISTHEP(IHEP).GE.147.AND.ISTHEP(IHEP).LE.149) THEN
+ JHEP=JMOHEP(2,IHEP)
+C BRW FIX 12/03/99
+ IF (JHEP.LE.0) THEN
+ KHEP=0
+ DO JHEP=1,NHEP
+ IF (ISTHEP(JHEP).GE.147.AND.ISTHEP(JHEP).LE.149
+ & .AND.JDAHEP(2,JHEP).LE.0) THEN
+ KHEP=KHEP+1
+ JMOHEP(2,IHEP)=JHEP
+ JDAHEP(2,JHEP)=IHEP
+ ENDIF
+ ENDDO
+ IF (KHEP.EQ.0) CALL HWWARN('HWCGSP',102,*999)
+ IF (KHEP.NE.1) CALL HWWARN('HWCGSP',103,*999)
+ ENDIF
+C END FIX
+C---CHECK FOR DECAYED HEAVY ANTIQUARKS
+ IF (ISTHEP(JHEP).EQ.155) THEN
+ JHEP=JDAHEP(1,JDAHEP(2,JHEP))
+ DO 10 J=JDAHEP(1,JHEP),JDAHEP(2,JHEP)
+ 10 IF (ISTHEP(J).EQ.149.AND.JDAHEP(2,J).EQ.0) GOTO 20
+ CALL HWWARN('HWCGSP',100,*999)
+ 20 JHEP=J
+ ENDIF
+ KHEP=JDAHEP(2,IHEP)
+C BRW FIX 12/03/99
+ IF (KHEP.LE.0) THEN
+ KHEP=0
+ DO JHEP=1,NHEP
+ IF (ISTHEP(JHEP).GE.147.AND.ISTHEP(JHEP).LE.149
+ & .AND.JMOHEP(2,JHEP).LE.0) THEN
+ KHEP=KHEP+1
+ JDAHEP(2,IHEP)=JHEP
+ JMOHEP(2,JHEP)=IHEP
+ ENDIF
+ ENDDO
+ IF (KHEP.EQ.0) CALL HWWARN('HWCGSP',104,*999)
+ IF (KHEP.NE.1) CALL HWWARN('HWCGSP',105,*999)
+ KHEP=JDAHEP(2,IHEP)
+ ENDIF
+C END FIX
+C---CHECK FOR DECAYED HEAVY QUARKS
+ IF (ISTHEP(KHEP).EQ.155) CALL HWWARN('HWCGSP',101,*999)
+ IF (IDHW(IHEP).EQ.13) THEN
+C---SPLIT A GLUON
+ LHEP=LHEP+2
+ MHEP=MHEP+2
+ IF(MHEP.GT.NMXHEP) CALL HWWARN('HWCGSP',106,*999)
+ 30 ID=HWRINT(1,NGSPL)
+ IF (PGSPL(ID).LT.PGSMX*HWR()) GOTO 30
+ PHEP(5,LHEP)=RMASS(ID)
+ PHEP(5,MHEP)=RMASS(ID)
+C---ASSUME ISOTROPIC ANGULAR DISTRIBUTION
+ IF (PHEP(5,IHEP).GT.PHEP(5,LHEP)+PHEP(5,MHEP)) THEN
+ CALL HWDTWO(PHEP(1,IHEP),PHEP(1,LHEP),
+ & PHEP(1,MHEP),PGSPL(ID),TWO,.TRUE.)
+ ELSE
+ PF=HWR()
+ CALL HWVSCA(4,PF,PHEP(1,IHEP),PHEP(1,LHEP))
+ CALL HWVDIF(4,PHEP(1,IHEP),PHEP(1,LHEP),PHEP(1,MHEP))
+ PHEP(5,LHEP)=PF*PHEP(5,IHEP)
+ PHEP(5,MHEP)=PHEP(5,IHEP)-PHEP(5,LHEP)
+ ENDIF
+ CALL HWUDKL(13,PHEP(1,IHEP),VHEP(1,LHEP))
+ CALL HWVSUM(4,VHEP(1,IHEP),VHEP(1,LHEP),VHEP(1,LHEP))
+ CALL HWVEQU(4,VHEP(1,LHEP),VHEP(1,MHEP))
+ IDHW(LHEP)=ID+6
+ IDHW(MHEP)=ID
+ IDHEP(MHEP)= IDPDG(ID)
+ IDHEP(LHEP)=-IDPDG(ID)
+ ISTHEP(IHEP)=2
+ ISTHEP(LHEP)=150
+ ISTHEP(MHEP)=150
+C---NEW COLOUR CONNECTIONS
+ IF(RPARTY.OR.JMOHEP(2,KHEP).EQ.IHEP) JMOHEP(2,KHEP)=LHEP
+ IF(RPARTY.OR.JDAHEP(2,JHEP).EQ.IHEP) JDAHEP(2,JHEP)=MHEP
+ JMOHEP(1,LHEP)=JMOHEP(1,IHEP)
+ JMOHEP(2,LHEP)=MHEP
+ JMOHEP(1,MHEP)=JMOHEP(1,IHEP)
+ JMOHEP(2,MHEP)=JHEP
+ JDAHEP(1,LHEP)=0
+ JDAHEP(2,LHEP)=KHEP
+ JDAHEP(1,MHEP)=0
+ JDAHEP(2,MHEP)=LHEP
+ JDAHEP(1,IHEP)=LHEP
+ JDAHEP(2,IHEP)=MHEP
+ ELSE
+C---COPY A NON-GLUON
+ LHEP=LHEP+1
+ MHEP=MHEP+1
+ IF(MHEP.GT.NMXHEP) CALL HWWARN('HWCGSP',107,*999)
+ CALL HWVEQU(5,PHEP(1,IHEP),PHEP(1,MHEP))
+ CALL HWVEQU(4,VHEP(1,IHEP),VHEP(1,MHEP))
+ IDHW(MHEP)=IDHW(IHEP)
+ IDHEP(MHEP)=IDHEP(IHEP)
+ IST=ISTHEP(IHEP)
+ ISTHEP(IHEP)=2
+ IF (IST.EQ.149) THEN
+ ISTHEP(MHEP)=150
+ ELSE
+ ISTHEP(MHEP)=IST+6
+ ENDIF
+C---NEW COLOUR CONNECTIONS
+ IF(RPARTY.OR.JMOHEP(2,KHEP).EQ.IHEP)
+ & JMOHEP(2,KHEP)=MHEP
+ IF(RPARTY.OR.(JHEP.NE.IHEP.AND.JDAHEP(2,JHEP).EQ.IHEP))
+ & JDAHEP(2,JHEP)=MHEP
+ JMOHEP(1,MHEP)=JMOHEP(1,IHEP)
+ JMOHEP(2,MHEP)=JMOHEP(2,IHEP)
+ JDAHEP(1,MHEP)=0
+ JDAHEP(2,MHEP)=JDAHEP(2,IHEP)
+ JDAHEP(1,IHEP)=MHEP
+ ENDIF
+ ENDIF
+ 100 CONTINUE
+ NHEP=MHEP
+ 999 END
+CDECK ID>, HWCHAD.
+*CMZ :- -26/04/91 14.00.57 by Federico Carminati
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWCHAD(JCL,ID1,ID3,ID2)
+C-----------------------------------------------------------------------
+C HADRONIZES CLUSTER JCL, CONSISTING OF PARTONS ID1,ID3
+C ID2 RETURNS PARTON-ANTIPARTON PAIR CREATED
+C (IN SPECIAL CLUSTER CODE - SEE HWCFLA)
+C
+C MODIFIED 15/11/99 TO SMEAR POSITIONS OF HADRONS BY 1/(CLUSTER MASS)
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWR,HWRGAU,HWVDOT,EM0,EM1,EM2,EMADU,EMSQ,
+ & PCMAX,PCM,PTEST,PCQK,PP(5),EMLOW,RMAT(3,3),CT,ST,CX,SX,HPSMR
+ INTEGER HWRINT,JCL,ID1,ID2,ID3,ID,IR1,IR2,NTRY,IDMIN,IMAX,I,MHEP,
+ & IM,JM,KM,IB
+ LOGICAL DIQK
+ EXTERNAL HWR,HWRINT
+ DIQK(ID)=ID.GT.3.AND.ID.LT.10
+ IF (IERROR.NE.0) RETURN
+ ID2=0
+ EM0=PHEP(5,JCL)
+ IR1=NCLDK(LOCN(ID1,ID3))
+ EM1=RMIN(ID1,ID3)
+ IF (ABS(EM0-EM1).LT.0.001) THEN
+C---SINGLE-HADRON CLUSTER
+ NHEP=NHEP+1
+ IF (NHEP.GT.NMXHEP) CALL HWWARN('HWCHAD',100,*999)
+ IDHW(NHEP)=IR1
+ IDHEP(NHEP)=IDPDG(IR1)
+ ISTHEP(NHEP)=191
+ JDAHEP(1,JCL)=NHEP
+ JDAHEP(2,JCL)=NHEP
+ CALL HWVEQU(5,PHEP(1,JCL),PHEP(1,NHEP))
+ CALL HWVSUM(4,VHEP(1,JCL),VTXPIP,VHEP(1,NHEP))
+ ELSE
+ NTRY=0
+ IDMIN=1
+ EMLOW=RMIN(ID1,1)+RMIN(1,ID3)
+ EMADU=RMIN(ID1,2)+RMIN(2,ID3)
+ IF (EMADU.LT.EMLOW) THEN
+ IDMIN=2
+ EMLOW=EMADU
+ ENDIF
+ EMSQ=EM0**2
+ PCMAX=EMSQ-EMLOW**2
+ IF (PCMAX.GE.ZERO) THEN
+C---SET UP TWO QUARK-ANTIQUARK PAIRS OR A
+C QUARK-DIQUARK AND AN ANTIDIQUARK-ANTIQUARK
+ PCMAX=PCMAX*(EMSQ-(RMIN(ID1,IDMIN)-RMIN(IDMIN,ID3))**2)
+ IMAX=12
+ IF (DIQK(ID1).OR.DIQK(ID3)) IMAX=3
+ DO 10 I=3,IMAX
+ IF (EM0.LT.RMIN(ID1,I)+RMIN(I,ID3)) GOTO 20
+ 10 CONTINUE
+ I=IMAX+1
+ 20 ID2=HWRINT(1,I-1)
+ IF (PWT(ID2).NE.ONE) THEN
+ IF (PWT(ID2).LT.HWR()) GOTO 20
+ ENDIF
+C---PICK TWO PARTICLES WITH THESE QUANTUM NUMBERS
+ NTRY=NTRY+1
+ 30 IR1=LOCN(ID1,ID2)+INT(RESN(ID1,ID2)*HWR())
+ IF (CLDKWT(IR1).LT.HWR()) GOTO 30
+ IR1=NCLDK(IR1)
+ 40 IR2=LOCN(ID2,ID3)+INT(RESN(ID2,ID3)*HWR())
+ IF (CLDKWT(IR2).LT.HWR()) GOTO 40
+ IR2=NCLDK(IR2)
+ EM1=RMASS(IR1)
+ EM2=RMASS(IR2)
+ PCM=EMSQ-(EM1+EM2)**2
+ IF (PCM.GT.ZERO) GOTO 70
+ 50 IF (NTRY.LE.NDTRY) GOTO 20
+C---CAN'T FIND A DECAY MODE - CHOOSE LIGHTEST
+ 60 ID2=HWRINT(1,2)
+ IR1=NCLDK(LOCN(ID1,ID2))
+ IR2=NCLDK(LOCN(ID2,ID3))
+ EM1=RMASS(IR1)
+ EM2=RMASS(IR2)
+ PCM=EMSQ-(EM1+EM2)**2
+ IF (PCM.GT.ZERO) GOTO 70
+ NTRY=NTRY+1
+ IF (NTRY.LE.NDTRY+50) GOTO 60
+ CALL HWWARN('HWCHAD',101,*999)
+C---DECAY IS ALLOWED
+ 70 PCM=PCM*(EMSQ-(EM1-EM2)**2)
+ IF (NTRY.GT.NCTRY) GOTO 80
+ PTEST=PCM*SWTEF(IR1)*SWTEF(IR2)
+ IF (PTEST.LT.PCMAX*HWR()**2) GOTO 20
+ ELSE
+C---ALLOW DECAY BY PI0 EMISSION IF ONLY POSSIBILITY
+ ID2=1
+ IR2=NCLDK(LOCN(1,1))
+ EM2=RMASS(IR2)
+ PCM=(EMSQ-(EM1+EM2)**2)*(EMSQ-(EM1-EM2)**2)
+ ENDIF
+C---DECAY IS CHOSEN. GENERATE DECAY MOMENTA
+C AND PUT PARTICLES IN /HEPEVT/
+ 80 IF (PCM.LT.ZERO) CALL HWWARN('HWCHAD',102,*999)
+ PCM=0.5*SQRT(PCM)/EM0
+ MHEP=NHEP+1
+ NHEP=NHEP+2
+ IF (NHEP.GT.NMXHEP) CALL HWWARN('HWCHAD',103,*999)
+ PHEP(5,MHEP)=EM1
+ PHEP(5,NHEP)=EM2
+C Decide if cluster contains a b-(anti)quark or not
+ IF (ID1.EQ.11.OR.ID2.EQ.11.OR.ID3.EQ.11) THEN
+ IB=2
+ ELSE
+ IB=1
+ ENDIF
+ IF (CLDIR(IB).NE.0) THEN
+ DO 110 IM=1,2
+ JM=JMOHEP(IM,JCL)
+ IF (JM.EQ.0) GOTO 110
+ IF (ISTHEP(JM).NE.158) GOTO 110
+C LOOK FOR PARENT PARTON
+ DO 100 KM=JMOHEP(1,JM)+1,JM
+ IF (ISTHEP(KM).EQ.2) THEN
+ IF (JDAHEP(1,KM).EQ.JM) THEN
+C FOUND PARENT PARTON
+ IF (IDHW(KM).NE.13) THEN
+C FIND ITS DIRECTION IN CLUSTER CMF
+ CALL HWULOF(PHEP(1,JCL),PHEP(1,KM),PP)
+ PCQK=PP(1)**2+PP(2)**2+PP(3)**2
+ IF (PCQK.GT.ZERO) THEN
+ PCQK=SQRT(PCQK)
+ IF (CLSMR(IB).GT.ZERO) THEN
+C DO GAUSSIAN SMEARING OF DIRECTION
+ 90 CT=ONE+CLSMR(IB)*LOG(HWR())
+ IF (CT.LT.-ONE) GOTO 90
+ ST=ONE-CT*CT
+ IF (ST.GT.ZERO) ST=SQRT(ST)
+ CALL HWRAZM( ONE,CX,SX)
+ CALL HWUROT(PP,CX,SX,RMAT)
+ PP(1)=ZERO
+ PP(2)=PCQK*ST
+ PP(3)=PCQK*CT
+ CALL HWUROB(RMAT,PP,PP)
+ ENDIF
+ PCQK=PCM/PCQK
+ IF (IM.EQ.2) PCQK=-PCQK
+ CALL HWVSCA(3,PCQK,PP,PHEP(1,MHEP))
+ PHEP(4,MHEP)=SQRT(PHEP(5,MHEP)**2+PCM**2)
+ CALL HWULOB(PHEP(1,JCL),PHEP(1,MHEP),PHEP(1,MHEP))
+ CALL HWVDIF(4,PHEP(1,JCL),PHEP(1,MHEP),PHEP(1,NHEP))
+ GOTO 130
+ ENDIF
+ ENDIF
+ GOTO 120
+ ENDIF
+ ELSEIF (ISTHEP(KM).GT.140) THEN
+C FINISHED THIS JET
+ GOTO 110
+ ENDIF
+ 100 CONTINUE
+ 110 CONTINUE
+ ENDIF
+ 120 CALL HWDTWO(PHEP(1,JCL),PHEP(1,MHEP),PHEP(1,NHEP),
+ & PCM,TWO,.TRUE.)
+ 130 IDHW(MHEP)=IR1
+ IDHW(NHEP)=IR2
+ IDHEP(MHEP)=IDPDG(IR1)
+ IDHEP(NHEP)=IDPDG(IR2)
+ ISTHEP(MHEP)=192
+ ISTHEP(NHEP)=192
+ JMOHEP(1,MHEP)=JCL
+C---SECOND MOTHER OF HADRON IS JET
+ JMOHEP(2,MHEP)=JMOHEP(1,JMOHEP(1,JCL))
+ JDAHEP(1,JCL)=MHEP
+ JDAHEP(2,JCL)=NHEP
+C---SMEAR HADRON POSITIONS
+ HPSMR=GEV2MM/PHEP(5,JCL)
+ DO I=1,4
+ VHEP(I,MHEP)=HWRGAU(I,ZERO,HPSMR)
+ ENDDO
+ VHEP(4,MHEP)=ABS(VHEP(4,MHEP))
+ & +SQRT(HWVDOT(3,VHEP(1,MHEP),VHEP(1,MHEP)))
+ CALL HWULB4(PHEP(1,JCL),VHEP(1,MHEP),VHEP(1,MHEP))
+ CALL HWVSUM(4,VHEP(1,JCL),VHEP(1,MHEP),VHEP(1,MHEP))
+ CALL HWVSUM(4,VTXPIP,VHEP(1,MHEP),VHEP(1,MHEP))
+ DO I=1,4
+ VHEP(I,NHEP)=HWRGAU(I,ZERO,HPSMR)
+ ENDDO
+ VHEP(4,NHEP)=ABS(VHEP(4,NHEP))
+ & +SQRT(HWVDOT(3,VHEP(1,NHEP),VHEP(1,NHEP)))
+ CALL HWULB4(PHEP(1,JCL),VHEP(1,NHEP),VHEP(1,NHEP))
+ CALL HWVSUM(4,VHEP(1,JCL),VHEP(1,NHEP),VHEP(1,NHEP))
+ CALL HWVSUM(4,VTXPIP,VHEP(1,NHEP),VHEP(1,NHEP))
+ ENDIF
+ ISTHEP(JCL)=180+MOD(ISTHEP(JCL),10)
+ JMOHEP(1,NHEP)=JCL
+ JMOHEP(2,NHEP)=JMOHEP(1,JMOHEP(1,JCL))
+ 999 END
+CDECK ID>, HWDBOS.
+*CMZ :- -23/05/96 18.34.17 by Mike Seymour
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDBOS(IBOSON)
+C-----------------------------------------------------------------------
+C DECAY GAUGE BOSONS (ALREADY FOUND BY HWDHAD)
+C USES SPIN DENSITY MATRIX IN RHOHEP (1ST CMPT=>-VE,2=>LONG,3=>+VE)
+C IF BOSON CAME FROM HIGGS DECAY, GIVE BOTH THE SAME HELICITY (EPR)
+C IF BOSON CAME FROM W+1JET, GIVE IT THE CORRECT DECAY CORRELATIONS
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWR,HWRUNI,HWUPCM,HWULDO,R(3,3),CV,CA,BR,PCM,
+ & PBOS(5),PMAX,PROB,RRLL,RLLR
+ INTEGER HWRINT,IBOS,IBOSON,IPAIR,ICMF,IOPT,IHEL,IMOTH,
+ & I,IQRK,IANT,ID,IQ
+ LOGICAL QUARKS
+ EXTERNAL HWR,HWRUNI,HWUPCM,HWULDO,HWRINT
+ IBOS=IBOSON
+ IF (IDHW(IBOS).LT.198.OR.IDHW(IBOS).GT.200)
+ & CALL HWWARN('HWDBOS',101,*999)
+ QUARKS=.FALSE.
+C---SEE IF IT IS PART OF A PAIR
+ IMOTH=JMOHEP(1,IBOS)
+ IPAIR=JMOHEP(2,IBOS)
+ ICMF=JMOHEP(1,IBOS)
+ IF (IDHW(ICMF).EQ.IDHW(IBOS).AND.ISTHEP(ICMF)/10.EQ.12)
+ & ICMF=JMOHEP(1,ICMF)
+ IOPT=0
+ IF (IPAIR.NE.0) THEN
+ IF (JMOHEP(2,IPAIR).NE.IBOS.OR.
+ & IDHW(IPAIR).LT.198.OR.IDHW(IPAIR).GT.200) IPAIR=0
+ ENDIF
+ IF (IPAIR.GT.0) IOPT=1
+C---SELECT DECAY PRODUCTS
+ 10 CALL HWDBOZ(IDHW(IBOS),IDN(1),IDN(2),CV,CA,BR,IOPT)
+C---V + 1JET DECAYS ARE NOW HANDLED HERE !
+ IF (IPRO.EQ.21) THEN
+ IQRK=IDHW(JMOHEP(1,ICMF))
+ IANT=IDHW(JMOHEP(2,ICMF))
+ IF (IQRK.EQ.13 .AND. IANT.LE.6) THEN
+ IQRK=JMOHEP(2,ICMF)
+ IANT=JDAHEP(2,ICMF)
+ ELSEIF (IQRK.EQ.13) THEN
+ IQRK=JDAHEP(2,ICMF)
+ IANT=JMOHEP(2,ICMF)
+ ELSEIF (IANT.EQ.13 .AND. IQRK.LE.6) THEN
+ IQRK=JMOHEP(1,ICMF)
+ IANT=JDAHEP(2,ICMF)
+ ELSEIF (IANT.EQ.13) THEN
+ IQRK=JDAHEP(2,ICMF)
+ IANT=JMOHEP(1,ICMF)
+ ELSEIF (IQRK.GT.IANT) THEN
+ IQRK=JMOHEP(2,ICMF)
+ IANT=JMOHEP(1,ICMF)
+ ELSE
+ IQRK=JMOHEP(1,ICMF)
+ IANT=JMOHEP(2,ICMF)
+ ENDIF
+ PHEP(5,NHEP+1)=RMASS(IDN(1))
+ PHEP(5,NHEP+2)=RMASS(IDN(2))
+ PCM=HWUPCM(PHEP(5,IBOS),PHEP(5,NHEP+1),PHEP(5,NHEP+2))
+ IF (PCM.LT.ZERO) CALL HWWARN('HWDBOS',103,*999)
+ IF (IDHW(IBOS).EQ.200) THEN
+ ID=IDN(1)
+ IF (ID.GT.120) ID=ID-110
+ IQ=IDHW(IQRK)
+ IF (IQ.GT.6) IQ=IQ-6
+ RRLL=(VFCH(IQ,1)**2+AFCH(IQ,1)**2)*
+ $ (VFCH(ID,1)**2+AFCH(ID,1)**2)
+ $ +4*VFCH(IQ,1)*AFCH(IQ,1)*
+ $ VFCH(ID,1)*AFCH(ID,1)
+ RLLR=(VFCH(IQ,1)**2+AFCH(IQ,1)**2)*
+ $ (VFCH(ID,1)**2+AFCH(ID,1)**2)
+ $ -4*VFCH(IQ,1)*AFCH(IQ,1)*
+ $ VFCH(ID,1)*AFCH(ID,1)
+ ELSE
+ RRLL=1
+ RLLR=0
+ ENDIF
+ PMAX=(RRLL+RLLR)
+ & *(HWULDO(PHEP(1,IANT),PHEP(1,IBOS))**2+
+ & HWULDO(PHEP(1,IQRK),PHEP(1,IBOS))**2)
+ 1 CALL HWDTWO(PHEP(1,IBOS),PHEP(1,NHEP+1),PHEP(1,NHEP+2),
+ & PCM,TWO,.TRUE.)
+ PROB=RRLL*(HWULDO(PHEP(1,IANT),PHEP(1,NHEP+1))**2+
+ & HWULDO(PHEP(1,IQRK),PHEP(1,NHEP+2))**2)+
+ & RLLR*(HWULDO(PHEP(1,IANT),PHEP(1,NHEP+2))**2+
+ & HWULDO(PHEP(1,IQRK),PHEP(1,NHEP+1))**2)
+ IF (PROB.GT.PMAX.OR.PROB.LT.ZERO)
+ & CALL HWWARN('HWDBOS',104,*999)
+ IF (PMAX*HWR().GT.PROB) GOTO 1
+ ELSE
+C---SELECT HELICITY, UNLESS IT IS THE SECOND OF A HIGGS DECAY (EPR)
+ IF (IPAIR.NE.IBOS .OR. IDHW(ICMF).NE.201) THEN
+ IF (RHOHEP(1,IBOS)+RHOHEP(2,IBOS)+RHOHEP(3,IBOS).LE.ZERO) THEN
+C---COPY PARENT HELICITY IF IT WAS A GAUGE BOSON
+ IF (IDHW(IMOTH).GE.198.AND.IDHW(IMOTH).LE.200) THEN
+ CALL HWVEQU(3,RHOHEP(1,IMOTH),RHOHEP(1,IBOS))
+ IF (RHOHEP(1,IBOS)+RHOHEP(2,IBOS)+RHOHEP(3,IBOS).GT.ZERO)
+ & GOTO 20
+C---MAY BE FROM A SUSY DECAY
+ ELSEIF (ABS(IDHEP(IMOTH)).LT.1000000) THEN
+ CALL HWWARN('HWDBOS',1,*999)
+ ENDIF
+ RHOHEP(1,IBOS)=1.
+ RHOHEP(2,IBOS)=1.
+ RHOHEP(3,IBOS)=1.
+ ENDIF
+ 20 IHEL=HWRINT(1,3)
+ IF (HWR().GT.RHOHEP(IHEL,IBOS)) GOTO 20
+ ENDIF
+C---SELECT DIRECTION OF FERMION
+ 30 COSTH=HWRUNI(0,-ONE,ONE)
+ IF (IHEL.EQ.1 .AND. (ONE+COSTH)**2.LT.HWR()*FOUR) GOTO 30
+ IF (IHEL.EQ.2 .AND. (ONE-COSTH**2).LT.HWR() ) GOTO 30
+ IF (IHEL.EQ.3 .AND. (ONE-COSTH)**2.LT.HWR()*FOUR) GOTO 30
+C---GENERATE DECAY RELATIVE TO Z-AXIS
+ PHEP(5,NHEP+1)=RMASS(IDN(1))
+ PHEP(5,NHEP+2)=RMASS(IDN(2))
+ PCM=HWUPCM(PHEP(5,IBOS),PHEP(5,NHEP+1),PHEP(5,NHEP+2))
+ IF (PCM.LT.ZERO) CALL HWWARN('HWDBOS',102,*999)
+ CALL HWRAZM(PCM*SQRT(1-COSTH**2),PHEP(1,NHEP+1),PHEP(2,NHEP+1))
+ PHEP(3,NHEP+1)=PCM*COSTH
+ PHEP(4,NHEP+1)=SQRT(PHEP(5,NHEP+1)**2+PCM**2)
+C---ROTATE SO THAT Z-AXIS BECOMES BOSON'S DIRECTION IN ORIGINAL CM FRAME
+ CALL HWULOF(PHEP(1,ICMF),PHEP(1,IBOS),PBOS)
+ CALL HWUROT(PBOS, ONE,ZERO,R)
+ CALL HWUROB(R,PHEP(1,NHEP+1),PHEP(1,NHEP+1))
+C---BOOST BACK TO LAB
+ CALL HWULOB(PHEP(1,IBOS),PHEP(1,NHEP+1),PHEP(1,NHEP+1))
+ CALL HWVDIF(4,PHEP(1,IBOS),PHEP(1,NHEP+1),PHEP(1,NHEP+2))
+ ENDIF
+C---STATUS, IDs AND POINTERS
+ ISTHEP(IBOS)=195
+ DO 50 I=1,2
+ ISTHEP(NHEP+I)=193
+ IDHW(NHEP+I)=IDN(I)
+ IDHEP(NHEP+I)=IDPDG(IDN(I))
+ JDAHEP(I,IBOS)=NHEP+I
+ JMOHEP(1,NHEP+I)=IBOS
+ JMOHEP(2,NHEP+I)=JMOHEP(1,IBOS)
+ 50 CONTINUE
+ NHEP=NHEP+2
+ IF (IDN(1).LE.12) THEN
+ ISTHEP(NHEP-1)=113
+ ISTHEP(NHEP)=114
+ JMOHEP(2,NHEP)=NHEP-1
+ JDAHEP(2,NHEP)=NHEP-1
+ JMOHEP(2,NHEP-1)=NHEP
+ JDAHEP(2,NHEP-1)=NHEP
+ QUARKS=.TRUE.
+ ENDIF
+C---IF FIRST OF A PAIR, DO SECOND DECAY
+ IF (IPAIR.NE.0 .AND. IPAIR.NE.IBOS) THEN
+ IBOS=IPAIR
+ GOTO 10
+ ENDIF
+C---IF QUARK DECAY, HADRONIZE
+ IF (QUARKS) THEN
+ EMSCA=PHEP(5,IBOS)
+ CALL HWBGEN
+ CALL HWDHOB
+ CALL HWCFOR
+ CALL HWCDEC
+ ENDIF
+ 999 END
+CDECK ID>, HWDBOZ.
+*CMZ :- -29/04/91 18.00.03 by Federico Carminati
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDBOZ(IDBOS,IFER,IANT,CV,CA,BR,IOPT)
+C-----------------------------------------------------------------------
+C CHOOSE DECAY MODE OF BOSON
+C IOPT=2 TO RESET COUNTERS, 1 FOR BOSON PAIR, 0 FOR ANY OTHERS
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWR,BRMODE(12,3),CV,CA,BR,BRLST,BRCOM,FACZ,
+ & FACW
+ INTEGER HWRINT,IDBOS,IDEC,IDMODE(2,12,3),IFER,IANT,IOPT,I1,I2,
+ & I1LST,I2LST,NWGLST,NUMDEC,NPAIR,MODTMP,JFER
+ LOGICAL GENLST
+ EXTERNAL HWR,HWRINT
+ SAVE FACW,FACZ,NWGLST,GENLST,NUMDEC,NPAIR,I1LST,I2LST,BRLST
+ DATA NWGLST,GENLST,NPAIR/-1,.FALSE.,0/
+C---STORE THE DECAY MODES (FERMION FIRST)
+ DATA IDMODE/ 2, 7, 4, 9, 6, 11, 2, 9, 4, 7,
+ & 122,127,124,129,126,131,8*0,
+ & 1, 8, 3, 10, 5, 12, 3, 8, 1, 10,
+ & 121,128,123,130,125,132,8*0,
+ & 1, 7, 2, 8, 3, 9, 4, 10, 5, 11, 6, 12,
+ & 121,127,123,129,125,131,122,128,124,130,126,132/
+C---STORE THE BRANCHING RATIOS TO THESE MODES
+ DATA BRMODE/0.321,0.321,0.000,0.017,0.017,0.108,0.108,0.108,4*0.0,
+ & 0.321,0.321,0.000,0.017,0.017,0.108,0.108,0.108,4*0.0,
+ & 0.154,0.120,0.154,0.120,0.152,0.000,
+ & 0.033,0.033,0.033,0.067,0.067,0.067/
+C---FACTORS FOR CV AND CA FOR W AND Z
+ DATA FACW,FACZ/2*0.0/
+ IF (FACZ.EQ.ZERO) FACZ=SQRT(SWEIN)
+ IF (FACW.EQ.ZERO) FACW=0.5/SQRT(2D0)
+ IF (IDBOS.LT.198.OR.IDBOS.GT.200) CALL HWWARN('HWDBOZ',101,*999)
+C---IF THIS IS A NEW EVENT SINCE LAST TIME, ZERO COUNTERS
+ IF (NWGTS.NE.NWGLST .OR.(GENEV.NEQV.GENLST).OR. IOPT.EQ.2) THEN
+ NPAIR=0
+ NUMDEC=0
+ NWGLST=NWGTS
+ GENLST=GENEV
+ IF (IOPT.EQ.2) RETURN
+ ENDIF
+ NUMDEC=NUMDEC+1
+ IF (NUMDEC.GT.MODMAX) CALL HWWARN('HWDBOZ',102,*999)
+C---IF PAIR OPTION SPECIFIED FOR THE FIRST TIME, MAKE CHOICE
+ IF (IOPT.EQ.1) THEN
+ IF (NUMDEC.GT.MODMAX-1) CALL HWWARN('HWDBOZ',103,*999)
+ IF (NPAIR.EQ.0) THEN
+ IF (HWR().GT.HALF) THEN
+ MODTMP=MODBOS(NUMDEC+1)
+ MODBOS(NUMDEC+1)=MODBOS(NUMDEC)
+ MODBOS(NUMDEC)=MODTMP
+ ENDIF
+ NPAIR=NUMDEC
+ ELSE
+ NPAIR=0
+ ENDIF
+ ENDIF
+C---SELECT USER'S CHOICE
+ IF (IDBOS.EQ.200) THEN
+ IF (MODBOS(NUMDEC).EQ.1) THEN
+ I1=1
+ I2=6
+ ELSEIF (MODBOS(NUMDEC).EQ.2) THEN
+ I1=7
+ I2=7
+ ELSEIF (MODBOS(NUMDEC).EQ.3) THEN
+ I1=8
+ I2=8
+ ELSEIF (MODBOS(NUMDEC).EQ.4) THEN
+ I1=9
+ I2=9
+ ELSEIF (MODBOS(NUMDEC).EQ.5) THEN
+ I1=7
+ I2=8
+ ELSEIF (MODBOS(NUMDEC).EQ.6) THEN
+ I1=10
+ I2=12
+ ELSEIF (MODBOS(NUMDEC).EQ.7) THEN
+ I1=5
+ I2=5
+ ELSE
+ I1=1
+ I2=12
+ ENDIF
+ ELSE
+ IF (MODBOS(NUMDEC).EQ.1) THEN
+ I1=1
+ I2=5
+ ELSEIF (MODBOS(NUMDEC).EQ.2) THEN
+ I1=6
+ I2=6
+ ELSEIF (MODBOS(NUMDEC).EQ.3) THEN
+ I1=7
+ I2=7
+ ELSEIF (MODBOS(NUMDEC).EQ.4) THEN
+ I1=8
+ I2=8
+ ELSEIF (MODBOS(NUMDEC).EQ.5) THEN
+ I1=6
+ I2=7
+ ELSE
+ I1=1
+ I2=8
+ ENDIF
+ ENDIF
+ 10 IDEC=HWRINT(I1,I2)
+ IF (HWR().GT.BRMODE(IDEC,IDBOS-197).AND.I1.NE.I2) GOTO 10
+ IFER=IDMODE(1,IDEC,IDBOS-197)
+ IANT=IDMODE(2,IDEC,IDBOS-197)
+C---CALCULATE BRANCHING RATIO
+C (RESULT IS NOT WELL-DEFINED AFTER THE FIRST CALL OF A PAIR)
+ BR=0
+ DO 20 IDEC=I1,I2
+ 20 BR=BR+BRMODE(IDEC,IDBOS-197)
+ IF (IOPT.EQ.1) THEN
+ IF (NPAIR.NE.0) THEN
+ I1LST=I1
+ I2LST=I2
+ BRLST=BR
+ ELSE
+ BRCOM=0
+ DO 30 IDEC=MAX(I1,I1LST),MIN(I2,I2LST)
+ 30 BRCOM=BRCOM+BRMODE(IDEC,IDBOS-197)
+ BR=2*BR*BRLST - BRCOM**2
+ ENDIF
+ ENDIF
+C---SET UP VECTOR AND AXIAL VECTOR COUPLINGS (NORMALIZED TO THE
+C CONVENTION WHERE THE WEAK CURRENT IS G*(CV-CA*GAM5) )
+ IF (IDBOS.EQ.200) THEN
+ IF (IFER.LE.6) THEN
+C Quark couplings
+ CV=VFCH(IFER,1)
+ CA=AFCH(IFER,1)
+ ELSE
+C lepton couplings
+ JFER=IFER-110
+ CV=VFCH(JFER,1)
+ CA=AFCH(JFER,1)
+ ENDIF
+ CV=CV * FACZ
+ CA=CA * FACZ
+ ELSE
+ CV=FACW
+ CA=FACW
+ ENDIF
+ 999 END
+CDECK ID>, HWDCHK.
+*CMZ :- -27/07/99 13.33.03 by Mike Seymour
+*-- Author : Ian Knowles
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDCHK(IDKY,L,*)
+C-----------------------------------------------------------------------
+C Checks line L of decay table is compatible with decay of particle
+C IDKY, tidies up the line and sets NPRODS.
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION EPS,QS,Q,DM
+ INTEGER IDKY,L,IFAULT,I,ID,J
+ PARAMETER (EPS=1.D-6)
+ IF (VTOCDK(IDKY).AND.VTORDK(IDKY)) RETURN 1
+ IFAULT=0
+ QS=FLOAT(ICHRG(IDKY))
+ IF (IDKY.LE.12.OR.(IDKY.GE.109.AND.IDKY.LE.120)
+ & .OR.(IDKY.GE.209.AND.IDKY.LE.220)
+ & .OR.(IDKY.GE.401.AND.IDKY.LE.424)) QS=QS/3.
+ DM=RMASS(IDKY)
+ NPRODS(L)=0
+ DO 10 I=1,5
+ ID=IDKPRD(I,L)
+ IF (ID.LT.0.OR.ID.EQ.20.OR.ID.GT.NRES) THEN
+ WRITE(6,20) L,RNAME(IDKY),(RNAME(IDKPRD(J,L)),J=1,5)
+ IFAULT=IFAULT+1
+ ELSEIF (ID.NE.0) THEN
+ IF (VTORDK(ID)) THEN
+ WRITE(6,30) L,RNAME(IDKY),(RNAME(IDKPRD(J,L)),J=1,5),RNAME(ID)
+ IFAULT=IFAULT+1
+ ENDIF
+ NPRODS(L)=NPRODS(L)+1
+ IDKPRD(NPRODS(L),L)=ID
+ Q=FLOAT(ICHRG(ID))
+ IF (ID.LE.12.OR.(ID.GE.109.AND.ID.LE.120)
+ & .OR.(ID.GE.209.AND.ID.LE.220)
+ & .OR.(ID.GE.401.AND.ID.LE.424)) Q=Q/3.
+ QS=QS-Q
+ DM=DM-RMASS(ID)
+ ENDIF
+ 10 CONTINUE
+C print any warnings
+ IF (NPRODS(L).EQ.0) THEN
+ WRITE(6,20) L,RNAME(IDKY),(RNAME(IDKPRD(I,L)),I=1,5)
+ IFAULT=IFAULT+1
+ ELSE
+ IF (ABS(QS).GT.EPS) THEN
+ WRITE(6,40) L,RNAME(IDKY),(RNAME(IDKPRD(I,L)),I=1,5),QS
+ IFAULT=IFAULT+1
+ ENDIF
+ IF (DM.LT.ZERO) THEN
+ WRITE(6,50) L,RNAME(IDKY),(RNAME(IDKPRD(I,L)),I=1,5),DM
+ IFAULT=IFAULT+1
+ ENDIF
+ ENDIF
+ 20 FORMAT(1X,'Line ',I4,' decay: ',A8,' --> ',4(A8,1X),A8/
+ & 1X,'contains no or unrecognised decay product(s)')
+ 30 FORMAT(1X,'Line ',I4,' decay: ',A8,' --> ',4(A8,1X),A8/
+ & 1X,'contains decay product ',A8,' which is vetoed')
+ 40 FORMAT(1X,'Line ',I4,' decay: ',A8,' --> ',4(A8,1X),A8/
+ & 1X,'violates charge conservation, Qin-Qout= ',F6.3)
+ 50 FORMAT(1X,'Line ',I4,' decay: ',A8,' --> ',4(A8,1X),A8/
+ & 1X,'is kinematically not allowed, Min-Mout= ',F10.3)
+ IF (IFAULT.NE.0) THEN
+ RETURN 1
+ ELSE
+ RETURN
+ ENDIF
+ END
+CDECK ID>, HWDCLE.
+*CMZ :- -28/01/92 12.34.44 by Mike Seymour
+*-- Author : Luca Stanco
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDCLE(IHEP)
+C-----------------------------------------------------------------------
+C INTERFACE TO QQ-CLEO MONTE CARLO (LS 11/12/91)
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER IHEP,IIHEP,NHEPHF,QQLMAT
+ LOGICAL QQLERR
+ CHARACTER*8 NAME
+ EXTERNAL QQLMAT
+C---QQ-CLEO COMMON'S
+C*** MCPARS.INC
+ INTEGER MCTRK, NTRKS, MCVRTX, NVTXS, MCHANS, MCDTRS, MPOLQQ
+ INTEGER MCNUM, MCSTBL, MCSTAB, MCTLQQ, MDECQQ
+ INTEGER MHLPRB, MHLLST, MHLANG, MCPLST, MFDECA
+ PARAMETER (MCTRK = 512)
+ PARAMETER (NTRKS = MCTRK)
+ PARAMETER (MCVRTX = 256)
+ PARAMETER (NVTXS = MCVRTX)
+ PARAMETER (MCHANS = 4000)
+ PARAMETER (MCDTRS = 8000)
+ PARAMETER (MPOLQQ = 300)
+ PARAMETER (MCNUM = 500)
+ PARAMETER (MCSTBL = 40)
+ PARAMETER (MCSTAB = 512)
+ PARAMETER (MCTLQQ = 100)
+ PARAMETER (MDECQQ = 300)
+ PARAMETER (MHLPRB = 500)
+ PARAMETER (MHLLST = 1000)
+ PARAMETER (MHLANG = 500)
+ PARAMETER (MCPLST = 200)
+ PARAMETER (MFDECA = 5)
+C*** MCPROP.INC
+ REAL AMASS, CHARGE, CTAU, SPIN, RWIDTH, RMASMN, RMASMX
+ REAL RMIXPP, RCPMIX
+ INTEGER NPMNQQ, NPMXQQ, IDMC, INVMC, LPARTY, CPARTY
+ INTEGER IMIXPP, ICPMIX
+ COMMON/MCMAS1/
+ * NPMNQQ, NPMXQQ,
+ * AMASS(-20:MCNUM), CHARGE(-20:MCNUM), CTAU(-20:MCNUM),
+ * IDMC(-20:MCNUM), SPIN(-20:MCNUM),
+ * RWIDTH(-20:MCNUM), RMASMN(-20:MCNUM), RMASMX(-20:MCNUM),
+ * LPARTY(-20:MCNUM), CPARTY(-20:MCNUM),
+ * IMIXPP(-20:MCNUM), RMIXPP(-20:MCNUM),
+ * ICPMIX(-20:MCNUM), RCPMIX(-20:MCNUM),
+ * INVMC(0:MCSTBL)
+C
+ INTEGER NPOLQQ, IPOLQQ
+ COMMON/MCPOL1/
+ * NPOLQQ, IPOLQQ(5,MPOLQQ)
+C
+ CHARACTER QNAME*10, PNAME*10
+ COMMON/MCNAMS/
+ * QNAME(37), PNAME(-20:MCNUM)
+C
+C*** MCCOMS.INC
+ INTEGER NCTLQQ, NDECQQ, IVRSQQ, IORGQQ, IRS1QQ
+ INTEGER IEVTQQ, IRUNQQ, IBMRAD
+ INTEGER NTRKMC, QQNTRK, NSTBMC, NSTBQQ, NCHGMC, NCHGQQ
+ INTEGER IRANQQ, IRANMC, IRANCC, IRS2QQ
+ INTEGER IPFTQQ, IPCDQQ, IPRNTV, ITYPEV, IDECSV, IDAUTV
+ INTEGER ISTBMC, NDAUTV
+ INTEGER IVPROD, IVDECA
+ REAL BFLDQQ
+ REAL ENERQQ, BEAMQQ, BMPSQQ, BMNGQQ, EWIDQQ, BWPSQQ, BWNGQQ
+ REAL BPOSQQ, BSIZQQ
+ REAL ECM, P4CMQQ, P4PHQQ, ENERNW, BEAMNW, BEAMP, BEAMN
+ REAL PSAV, P4QQ, HELCQQ
+ CHARACTER DATEQQ*20, TIMEQQ*20, FOUTQQ*80, FCTLQQ*80, FDECQQ*80
+ CHARACTER FGEOQQ*80
+ CHARACTER CCTLQQ*80, CDECQQ*80
+C
+ COMMON/MCCM1A/
+ * NCTLQQ, NDECQQ, IVRSQQ, IORGQQ, IRS1QQ(3), BFLDQQ,
+ * ENERQQ, BEAMQQ, BMPSQQ, BMNGQQ, EWIDQQ, BWPSQQ, BWNGQQ,
+ * BPOSQQ(3), BSIZQQ(3),
+ * IEVTQQ, IRUNQQ,
+ * IBMRAD, ECM, P4CMQQ(4), P4PHQQ(4),
+ * ENERNW, BEAMNW, BEAMP, BEAMN,
+ * NTRKMC, QQNTRK, NSTBMC, NSTBQQ, NCHGMC, NCHGQQ,
+ * IRANQQ(2), IRANMC(2), IRANCC(2), IRS2QQ(5),
+ * IPFTQQ(MCTRK), IPCDQQ(MCTRK), IPRNTV(MCTRK), ITYPEV(MCTRK,2),
+ * IDECSV(MCTRK), IDAUTV(MCTRK), ISTBMC(MCTRK), NDAUTV(MCTRK),
+ * IVPROD(MCTRK), IVDECA(MCTRK),
+ * PSAV(MCTRK,4), HELCQQ(MCTRK), P4QQ(4,MCTRK)
+C
+ COMMON/MCCM1B/
+ * DATEQQ, TIMEQQ, FOUTQQ, FCTLQQ, FDECQQ, FGEOQQ,
+ * CCTLQQ(MCTLQQ), CDECQQ(MDECQQ)
+ INTEGER IDSTBL
+ COMMON/MCCM1C/
+ * IDSTBL(MCSTAB)
+C
+ INTEGER IFINAL(MCTRK), IFINSV(MCSTAB), NFINAL
+ EQUIVALENCE (IFINAL,ISTBMC), (IFINSV,IDSTBL), (NFINAL,NSTBMC)
+C
+ INTEGER NVRTX, ITRKIN, NTRKOU, ITRKOU, IVKODE
+ REAL XVTX, TVTX, RVTX
+ COMMON/MCCM2/
+ * NVRTX, XVTX(MCVRTX,3), TVTX(MCVRTX), RVTX(MCVRTX),
+ * ITRKIN(MCVRTX), NTRKOU(MCVRTX), ITRKOU(MCVRTX),
+ * IVKODE(MCVRTX)
+C*** MCGEN.INC
+ INTEGER QQIST,QQIFR,QQN,QQK,QQMESO,QQNC,QQKC,QQLASTN
+ REAL QQPUD,QQPS1,QQSIGM,QQMAS,QQPAR,QQCMIX,QQCND,QQBSPI,QQBSYM,QQP
+ REAL QQPC,QQCZF
+C
+ COMMON/DATA1/QQIST,QQIFR,QQPUD,QQPS1,QQSIGM,QQMAS(15),QQPAR(25)
+ COMMON/DATA2/QQCZF(15),QQMESO(36),QQCMIX(6,2)
+ COMMON/DATA3/QQCND(3)
+ COMMON/DATA5/QQBSPI(5),QQBSYM(3)
+ COMMON/JET/QQN,QQK(250,2),QQP(250,5),QQNC,QQKC(10),QQPC(10,4),
+ * QQLASTN
+C---
+ IF(FSTEVT) THEN
+C---INITIALIZE QQ-CLEO
+ CALL QQINIT(QQLERR)
+ IF(QQLERR) CALL HWWARN('HWDEUR',500,*999)
+ ENDIF
+C---CONSTRUCT THE HADRON FOR QQ-CLEO
+C NOTE: THE IDPDG CODE IS PROVIDED THROUGH THE QQLMAT ROUTINE
+C FROM THE CLEO PACKAGE (QQ-CLEO <--> IDPDG CODE TRANSFORMATION)
+ QQN=1
+ IDHEP(IHEP)=IDPDG(IDHW(IHEP))
+ QQK(1,1)=0
+ QQK(1,2)=QQLMAT(IDHEP(IHEP),1)
+ QQP(1,1)=PHEP(1,IHEP)
+ QQP(1,2)=PHEP(2,IHEP)
+ QQP(1,3)=PHEP(3,IHEP)
+ QQP(1,5)=AMASS(QQK(1,2))
+ QQP(1,4)=SQRT(QQP(1,5)**2+QQP(1,1)**2+QQP(1,2)**2+QQP(1,3)**2)
+C---LET QQ-CLEO DO THE JOB
+ QQNTRK=0
+ NVRTX=0
+ CALL DECADD(.FALSE.)
+C---UPDATE THE HERWIG TABLE : LOOP OVER QQN-CLEO FINAL PARTICLES
+ DO 40 IIHEP=1,QQN
+ NHEP=NHEP+1
+ ISTHEP(NHEP)=198
+ IF(ITYPEV(IIHEP,2).GE.0) ISTHEP(NHEP)=1
+ IDHEP(NHEP)=QQLMAT(ITYPEV(IIHEP,1),2)
+ CALL HWUIDT(1,IDHEP(NHEP),IDHW(NHEP),NAME)
+ IF(IIHEP.EQ.1) THEN
+ ISTHEP(IHEP)=199
+ JDAHEP(1,IHEP)=NHEP
+ JDAHEP(2,IHEP)=NHEP
+ ISTHEP(NHEP)=199
+ NHEPHF=NHEP
+ JMOHEP(1,NHEP)=IHEP
+ JMOHEP(2,NHEP)=IHEP
+ ELSE
+ JMOHEP(1,NHEP)=IPRNTV(IIHEP)+NHEPHF-1
+ JMOHEP(2,NHEP)=NHEPHF
+ ENDIF
+ JDAHEP(1,NHEP)=0
+ JDAHEP(2,NHEP)=0
+ IF(NDAUTV(IIHEP).GT.0) THEN
+ JDAHEP(1,NHEP)=IDAUTV(IIHEP)+NHEPHF-1
+ JDAHEP(2,NHEP)=JDAHEP(1,NHEP)+NDAUTV(IIHEP)-1
+ ENDIF
+ PHEP(1,NHEP)=QQP(IIHEP,1)
+ PHEP(2,NHEP)=QQP(IIHEP,2)
+ PHEP(3,NHEP)=QQP(IIHEP,3)
+ PHEP(4,NHEP)=QQP(IIHEP,4)
+ PHEP(5,NHEP)=QQP(IIHEP,5)
+ VHEP(1,NHEP)=XVTX(IVPROD(IIHEP),1)
+ VHEP(2,NHEP)=XVTX(IVPROD(IIHEP),2)
+ VHEP(3,NHEP)=XVTX(IVPROD(IIHEP),3)
+ VHEP(4,NHEP)=0.
+ 40 CONTINUE
+ 999 END
+CDECK ID>, HWDEUR.
+*CMZ :- -28/01/92 12.34.44 by Mike Seymour
+*-- Author : Luca Stanco
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDEUR(IHEP)
+C-----------------------------------------------------------------------
+C INTERFACE TO EURODEC PACKAGE (LS 10/29/91)
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER IHEP,IIHEP,NHEPHF,IEUPDG,IPDGEU
+ CHARACTER*8 NAME
+C---EURODEC COMMON'S : INITIAL INPUT
+ INTEGER EULUN0,EULUN1,EULUN2,EURUN,EUEVNT
+ CHARACTER*4 EUDATD,EUTIT
+ REAL AMINIE(12),EUWEI
+ COMMON/INPOUT/EULUN0,EULUN1,EULUN2
+ COMMON/FILNAM/EUDATD,EUTIT
+ COMMON/HVYINI/AMINIE
+ COMMON/RUNINF/EURUN,EUEVNT,EUWEI
+C---EURODEC WORKING COMMON'S
+ INTEGER NPMAX,NTMAX
+ PARAMETER (NPMAX=18,NTMAX=2000)
+ INTEGER EUNP,EUIP(NPMAX),EUPHEL(NPMAX),EUTEIL,EUINDX(NTMAX),
+ & EUORIG(NTMAX),EUDCAY(NTMAX),EUTHEL(NTMAX)
+ REAL EUAPM(NPMAX),EUPCM(5,NPMAX),EUPVTX(3,NPMAX),EUPTEI(5,NTMAX),
+ & EUSECV(3,NTMAX)
+ COMMON/MOMGEN/EUNP,EUIP,EUAPM,EUPCM,EUPHEL,EUPVTX
+ COMMON/RESULT/EUTEIL,EUPTEI,EUINDX,EUORIG,EUDCAY,EUTHEL,EUSECV
+C---EURODEC COMMON'S FOR DECAY PROPERTIES
+ INTEGER NGMAX,NCMAX
+ PARAMETER (NGMAX=400,NCMAX=9000)
+ INTEGER EUNPA,EUIPC(NGMAX),EUIPDG(NGMAX),EUIDP(NGMAX),
+ & EUCONV(NCMAX)
+ REAL EUPM(NGMAX),EUPLT(NGMAX)
+ COMMON/PCTABL/EUNPA,EUIPC,EUIPDG,EUPM,EUPLT,EUIDP
+ COMMON/CONVRT/EUCONV
+C---
+ IF(FSTEVT) THEN
+C---CHANGE HERE THE DEFAULT VALUES OF EURODEC COMMON'S
+C
+C---INITIALIZE EURODEC COMMON'S
+CC CALL EUDCIN
+C---INITIALIZE EURODEC
+ CALL EUDINI
+ ENDIF
+C---CONSTRUCT THE HADRON FOR EURODEC FROM ID1,ID2
+ EUNP=1
+ IDHEP(IHEP)=IDPDG(IDHW(IHEP))
+ EUIP(1)=IPDGEU(IDHEP(IHEP))
+ EUAPM(1)=EUPM(EUCONV(IABS(EUIP(1))))
+ EUPCM(1,1)=PHEP(1,IHEP)
+ EUPCM(2,1)=PHEP(2,IHEP)
+ EUPCM(3,1)=PHEP(3,IHEP)
+ EUPCM(5,1)=SQRT(PHEP(1,IHEP)**2+PHEP(2,IHEP)**2+PHEP(3,IHEP)**2)
+ EUPCM(4,1)=SQRT(EUPCM(5,1)**2+EUAPM(1)**2)
+C NOT POLARIZED HADRONS
+ EUPHEL(1)=0
+C HADRONS START FROM PRIMARY VERTEX
+ EUPVTX(1,1)=0.
+ EUPVTX(2,1)=0.
+ EUPVTX(3,1)=0.
+C---LET EURODEC DO THE JOB
+ EUTEIL=0
+ CALL FRAGMT(1,1,0)
+C---UPDATE THE HERWIG TABLE : LOOP OVER N-EURODEC FINAL PARTICLES
+ DO 40 IIHEP=1,EUTEIL
+ NHEP=NHEP+1
+ ISTHEP(NHEP)=198
+ IF(EUDCAY(IIHEP).EQ.0) ISTHEP(NHEP)=1
+ IDHEP(NHEP)=IEUPDG(EUINDX(IIHEP))
+ CALL HWUIDT(1,IDHEP(NHEP),IDHW(NHEP),NAME)
+ IF(IIHEP.EQ.1) THEN
+ ISTHEP(IHEP)=199
+ JDAHEP(1,IHEP)=NHEP
+ JDAHEP(2,IHEP)=NHEP
+ ISTHEP(NHEP)=199
+ NHEPHF=NHEP
+ JMOHEP(1,NHEP)=IHEP
+ JMOHEP(2,NHEP)=IHEP
+ JDAHEP(1,NHEP)=EUDCAY(IIHEP)/10000+NHEPHF-1
+ JDAHEP(2,NHEP)=MOD(EUDCAY(IIHEP),10000)+NHEPHF-1
+ ELSE
+ JMOHEP(1,NHEP)=MOD(EUORIG(IIHEP),10000)+NHEPHF-1
+ JMOHEP(2,NHEP)=NHEPHF
+ JDAHEP(1,NHEP)=EUDCAY(IIHEP)/10000+NHEPHF-1
+ JDAHEP(2,NHEP)=MOD(EUDCAY(IIHEP),10000)+NHEPHF-1
+ ENDIF
+ PHEP(1,NHEP)=EUPTEI(1,IIHEP)
+ PHEP(2,NHEP)=EUPTEI(2,IIHEP)
+ PHEP(3,NHEP)=EUPTEI(3,IIHEP)
+ PHEP(4,NHEP)=EUPTEI(4,IIHEP)
+ PHEP(5,NHEP)=EUPTEI(5,IIHEP)
+ VHEP(1,NHEP)=EUSECV(1,IIHEP)
+ VHEP(2,NHEP)=EUSECV(2,IIHEP)
+ VHEP(3,NHEP)=EUSECV(3,IIHEP)
+ VHEP(4,NHEP)=0.
+ IF (IIHEP.GT.NTMAX) CALL HWWARN('HWDEUR',99,*999)
+ 40 CONTINUE
+ 999 END
+CDECK ID>, HWDFOR.
+*CMZ :- -01/04/99 19.52.44 by Mike Seymour
+*-- Author : Ian Knowles
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDFOR(P0,P1,P2,P3,P4)
+C-----------------------------------------------------------------------
+C Generates 4-body decay 0->1+2+3+4 using pure phase space
+C-----------------------------------------------------------------------
+ IMPLICIT NONE
+ DOUBLE PRECISION HWR,P0(5),P1(5),P2(5),P3(5),P4(5),B,C,AA,BB,
+ & CC,DD,EE,TT,S1,RS1,FF,S2,PP,QQ,RR,P1CM,P234(5),P2CM,P34(5),P3CM
+ DOUBLE PRECISION TWO
+ PARAMETER (TWO=2.D0)
+ EXTERNAL HWR
+ B=P0(5)-P1(5)
+ C=P2(5)+P3(5)+P4(5)
+ IF (B.LT.C) CALL HWWARN('HWDFOR',100,*999)
+ AA=(P0(5)+P1(5))**2
+ BB=B**2
+ CC=C**2
+ DD=(P3(5)+P4(5))**2
+ EE=(P3(5)-P4(5))**2
+ TT=(B-C)*P0(5)**7/16
+C Select squared masses S1 and S2 of 234 and 34 subsystems
+ 10 S1=BB+HWR()*(CC-BB)
+ RS1=SQRT(S1)
+ FF=(RS1-P2(5))**2
+ S2=DD+HWR()*(FF-DD)
+ PP=(AA-S1)*(BB-S1)
+ QQ=((RS1+P2(5))**2-S2)*(FF-S2)/S1
+ RR=(S2-DD)*(S2-EE)/S2
+ IF (PP*QQ*RR*(FF-DD)**2.LT.TT*S1*S2*HWR()**2) GOTO 10
+C Do two body decays: 0-->1+234, 234-->2+34 and 34-->3+4
+ P1CM=SQRT(PP/4)/P0(5)
+ P234(5)=RS1
+ P2CM=SQRT(QQ/4)
+ P34(5)=SQRT(S2)
+ P3CM=SQRT(RR/4)
+ CALL HWDTWO(P0 ,P1,P234,P1CM,TWO,.TRUE.)
+ CALL HWDTWO(P234,P2,P34 ,P2CM,TWO,.TRUE.)
+ CALL HWDTWO(P34 ,P3,P4 ,P3CM,TWO,.TRUE.)
+ 999 END
+CDECK ID>, HWDFIV.
+*CMZ :- -01/04/99 19.52.44 by Mike Seymour
+*-- Author : Ian Knowles
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDFIV(P0,P1,P2,P3,P4,P5)
+C-----------------------------------------------------------------------
+C Generates 5-body decay 0->1+2+3+4+5 using pure phase space
+C-----------------------------------------------------------------------
+ IMPLICIT NONE
+ DOUBLE PRECISION HWR,P0(5),P1(5),P2(5),P3(5),P4(5),P5(5),B,C,
+ & AA,BB,CC,DD,EE,FF,TT,S1,RS1,GG,S2,RS2,HH,S3,PP,QQ,RR,SS,P1CM,
+ & P2345(5),P2CM,P345(5),P3CM,P45(5),P4CM
+ DOUBLE PRECISION TWO
+ PARAMETER (TWO=2.D0)
+ EXTERNAL HWR
+ B=P0(5)-P1(5)
+ C=P2(5)+P3(5)+P4(5)+P5(5)
+ IF (B.LT.C) CALL HWWARN('HWDFIV',100,*999)
+ AA=(P0(5)+P1(5))**2
+ BB=B**2
+ CC=C**2
+ DD=(P3(5)+P4(5)+P5(5))**2
+ EE=(P4(5)+P5(5))**2
+ FF=(P4(5)-P5(5))**2
+ TT=(B-C)*P0(5)**11/729
+C Select squared masses S1, S2 and S3 of 2345, 345 and 45 subsystems
+ 10 S1=BB+HWR()*(CC-BB)
+ RS1=SQRT(S1)
+ GG=(RS1-P2(5))**2
+ S2=DD+HWR()*(GG-DD)
+ RS2=SQRT(S2)
+ HH=(RS2-P3(5))**2
+ S3=EE+HWR()*(HH-EE)
+ PP=(AA-S1)*(BB-S1)
+ QQ=((RS1+P2(5))**2-S2)*(GG-S2)/S1
+ RR=((RS2+P3(5))**2-S3)*(HH-S3)/S2
+ SS=(S3-EE)*(S3-FF)/S3
+ IF (PP*QQ*RR*SS*((GG-DD)*(HH-EE))**2.LT.TT*S1*S2*S3*HWR()**2)
+ & GOTO 10
+C Do two body decays: 0-->1+2345, 2345-->2+345, 345-->3+45 and 45-->4+5
+ P1CM=SQRT(PP/4)/P0(5)
+ P2345(5)=RS1
+ P2CM=SQRT(QQ/4)
+ P345(5)=RS2
+ P3CM=SQRT(RR/4)
+ P45(5)=SQRT(S3)
+ P4CM=SQRT(SS/4)
+ CALL HWDTWO(P0 ,P1,P2345,P1CM,TWO,.TRUE.)
+ CALL HWDTWO(P2345,P2,P345 ,P2CM,TWO,.TRUE.)
+ CALL HWDTWO(P345 ,P3,P45 ,P3CM,TWO,.TRUE.)
+ CALL HWDTWO(P45 ,P4,P5 ,P4CM,TWO,.TRUE.)
+ 999 END
+CDECK ID>, HWDHAD.
+*CMZ :- -26/04/91 14.01.26 by Federico Carminati
+*-- Author : Ian Knowles, Bryan Webber & Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDHAD
+C-----------------------------------------------------------------------
+C GENERATES DECAYS OF UNSTABLE HADRONS AND LEPTONS
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWR,HWULDO,RN,BF,COSANG,RSUM,DIST(4),VERTX(4),
+ & PMIX,WTMX,WTMX2,XS,DOT1,DOT2,HWDPWT,HWDWWT,XXX,YYY
+ INTEGER IHEP,ID,MHEP,IDM,I,IDS,IM,MO,IPDG
+ LOGICAL STABLE
+ EXTERNAL HWR,HWDPWT,HWDWWT,HWULDO
+ IF (IERROR.NE.0) RETURN
+ DO 100 IHEP=1,NMXHEP
+ IF (IHEP.GT.NHEP) THEN
+ ISTAT=90
+ RETURN
+ ELSEIF (ISTHEP(IHEP).EQ.120 .AND.
+ & JDAHEP(1,IHEP).EQ.IHEP.AND.JDAHEP(2,IHEP).EQ.IHEP) THEN
+C---COPY COLOUR SINGLET CMF
+ NHEP=NHEP+1
+ IF (NHEP.GT.NMXHEP) CALL HWWARN('HWDHAD',100,*999)
+ CALL HWVEQU(5,PHEP(1,IHEP),PHEP(1,NHEP))
+ CALL HWVEQU(4,VHEP(1,IHEP),VHEP(1,NHEP))
+ IDHW(NHEP)=IDHW(IHEP)
+ IDHEP(NHEP)=IDHEP(IHEP)
+ ISTHEP(NHEP)=190
+ JMOHEP(1,NHEP)=IHEP
+ JMOHEP(2,NHEP)=NHEP
+ JDAHEP(2,NHEP)=NHEP
+ JDAHEP(1,IHEP)=NHEP
+ JDAHEP(2,IHEP)=NHEP
+ ELSEIF (ISTHEP(IHEP).GE.190.AND.ISTHEP(IHEP).LE.193) THEN
+C---FIRST CHECK FOR STABILITY
+ ID=IDHW(IHEP)
+ IF (RSTAB(ID)) THEN
+ ISTHEP(IHEP)=1
+ JDAHEP(1,IHEP)=0
+ JDAHEP(2,IHEP)=0
+C---SPECIAL FOR GAUGE BOSON DECAY
+ IF (ID.GE.198.AND.ID.LE.200) CALL HWDBOS(IHEP)
+C---SPECIAL FOR HIGGS BOSON DECAY
+ IF (ID.EQ.201) CALL HWDHIG(ZERO)
+ ELSE
+C---UNSTABLE.
+C Calculate position of decay vertex
+ IF (DKLTM(ID).EQ.ZERO) THEN
+ CALL HWVEQU(4,VHEP(1,IHEP),VERTX)
+ MHEP=IHEP
+ IDM=ID
+ ELSE
+ CALL HWUDKL(ID,PHEP(1,IHEP),DIST)
+ CALL HWVSUM(4,VHEP(1,IHEP),DIST,VERTX)
+ IF (MAXDKL) THEN
+ CALL HWDXLM(VERTX,STABLE)
+ IF (STABLE) THEN
+ ISTHEP(IHEP)=1
+ JDAHEP(1,IHEP)=0
+ JDAHEP(2,IHEP)=0
+ GOTO 100
+ ENDIF
+ ENDIF
+ IF (MIXING.AND.(ID.EQ.221.OR.ID.EQ.223.OR.
+ & ID.EQ.245.OR.ID.EQ.247)) THEN
+C Select flavour of decaying b-meson allowing for flavour oscillation
+ IDS=MOD(ID,3)
+ XXX=XMRCT(IDS)*DIST(4)/PHEP(4,IHEP)
+ YYY=YMRCT(IDS)*DIST(4)/PHEP(4,IHEP)
+ IF (ABS(YYY).LT.10) THEN
+ PMIX=HALF*(ONE-COS(XXX)/COSH(YYY))
+ ELSE
+ PMIX=HALF
+ ENDIF
+ IF (HWR().LE.PMIX) THEN
+ IF (ID.LE.223) THEN
+ IDM=ID+24
+ ELSE
+ IDM=ID-24
+ ENDIF
+ ELSE
+ IDM=ID
+ ENDIF
+C Introduce a decaying neutral b-meson
+ IF (NHEP+1.GT.NMXHEP) CALL HWWARN('HWDHAD',101,*999)
+ MHEP=NHEP+1
+ ISTHEP(MHEP)=ISTHEP(IHEP)
+ ISTHEP(IHEP)=200
+ JDAHEP(1,IHEP)=MHEP
+ JDAHEP(2,IHEP)=MHEP
+ IDHW(MHEP)=IDM
+ IDHEP(MHEP)=IDPDG(IDM)
+ JMOHEP(1,MHEP)=IHEP
+ JMOHEP(2,MHEP)=JMOHEP(2,IHEP)
+ CALL HWVEQU(5,PHEP(1,IHEP),PHEP(1,MHEP))
+ CALL HWVEQU(4,VERTX,VHEP(1,MHEP))
+ NHEP=NHEP+1
+ ELSE
+ MHEP=IHEP
+ IDM=ID
+ ENDIF
+ ENDIF
+C Use CLEO/EURODEC packages for b-hadrons if requested
+ IF ((IDM.GE.221.AND.IDM.LE.231).OR.
+ & (IDM.GE.245.AND.IDM.LE.254)) THEN
+ IF (BDECAY.EQ.'CLEO') THEN
+ CALL HWDCLE(MHEP)
+ GOTO 100
+ ELSEIF (BDECAY.EQ.'EURO') THEN
+ CALL HWDEUR(MHEP)
+ GOTO 100
+ ENDIF
+ ENDIF
+C Choose decay mode
+ ISTHEP(MHEP)=ISTHEP(MHEP)+5
+ RN=HWR()
+ BF=0.
+ IM=LSTRT(IDM)
+ DO 10 I=1,NMODES(IDM)
+ BF=BF+BRFRAC(IM)
+ IF (BF.GE.RN) GOTO 20
+ 10 IM=LNEXT(IM)
+ CALL HWWARN('HWDHAD',50,*20)
+ 20 IF ((IDKPRD(1,IM).GE.1.AND.IDKPRD(1,IM).LE.13).OR.
+ & (IDKPRD(3,IM).GE.1.AND.IDKPRD(3,IM).LE.13)) THEN
+C Partonic decay of a heavy-(b,c)-hadron, store details
+ NQDK=NQDK+1
+ IF (NQDK.GT.NMXQDK) CALL HWWARN('HWDHAD',102,*999)
+ LOCQ(NQDK)=MHEP
+ IMQDK(NQDK)=IM
+ CALL HWVEQU(4,VERTX,VTXQDK(1,NQDK))
+ GOTO 100
+ ELSE
+C Exclusive decay, add decay products to event record
+ IF (NHEP+NPRODS(IM).GT.NMXHEP)
+ & CALL HWWARN('HWDHAD',103,*999)
+ JDAHEP(1,MHEP)=NHEP+1
+ DO 30 I=1,NPRODS(IM)
+ NHEP=NHEP+1
+ IDHW(NHEP)=IDKPRD(I,IM)
+ IDHEP(NHEP)=IDPDG(IDKPRD(I,IM))
+ ISTHEP(NHEP)=193
+ JMOHEP(1,NHEP)=MHEP
+ JMOHEP(2,NHEP)=JMOHEP(2,MHEP)
+ PHEP(5,NHEP)=RMASS(IDKPRD(I,IM))
+ 30 CALL HWVEQU(4,VERTX,VHEP(1,NHEP))
+ JDAHEP(2,MHEP)=NHEP
+ ENDIF
+C Next choose momenta:
+ IF (NPRODS(IM).EQ.1) THEN
+C 1-body decay: K0(BR) --> K0S,K0L
+ CALL HWVEQU(4,PHEP(1,MHEP),PHEP(1,NHEP))
+ ELSEIF (NPRODS(IM).EQ.2) THEN
+C 2-body decay
+C---SPECIAL TREATMENT OF POLARIZED MESONS
+ COSANG=TWO
+ IF (ID.EQ.IDHW(JMOHEP(1,MHEP))) THEN
+ MO=JMOHEP(1,MHEP)
+ RSUM=0
+ DO 40 I=1,3
+ 40 RSUM=RSUM+RHOHEP(I,MO)
+ IF (RSUM.GT.ZERO) THEN
+ RSUM=RSUM*HWR()
+ IF (RSUM.LT.RHOHEP(1,MO)) THEN
+C---(1+COSANG)**2
+ COSANG=MAX(HWR(),HWR(),HWR())*TWO-ONE
+ ELSEIF (RSUM.LT.RHOHEP(1,MO)+RHOHEP(2,MO)) THEN
+C---1-COSANG**2
+ COSANG=2*COS((ACOS(HWR()*TWO-ONE)+PIFAC)/THREE)
+ ELSE
+C---(1-COSANG)**2
+ COSANG=MIN(HWR(),HWR(),HWR())*TWO-ONE
+ ENDIF
+ ENDIF
+ ENDIF
+ CALL HWDTWO(PHEP(1,MHEP),PHEP(1,NHEP-1),
+ & PHEP(1,NHEP),CMMOM(IM),COSANG,.FALSE.)
+ ELSEIF (NPRODS(IM).EQ.3) THEN
+C 3-body decay
+ IF (NME(IM).EQ.100) THEN
+C Use free massless (V-A)*(V-A) Matrix Element
+ CALL HWDTHR(PHEP(1,MHEP),PHEP(1,NHEP-1),PHEP(1,NHEP-2),
+ & PHEP(1,NHEP),HWDWWT)
+ ELSEIF (NME(IM).EQ.101) THEN
+C Use bound massless (V-A)*(V-A) Matrix Element
+ WTMX=((PHEP(5,MHEP)-PHEP(5,NHEP))
+ & *(PHEP(5,MHEP)+PHEP(5,NHEP))
+ & +(PHEP(5,NHEP-1)-PHEP(5,NHEP-2))
+ & *(PHEP(5,NHEP-1)+PHEP(5,NHEP-2)))/TWO
+ WTMX2=WTMX**2
+ IPDG=ABS(IDHEP(MHEP))
+ XS=ONE-MAX(RMASS(MOD(IPDG/1000,10)),
+ & RMASS(MOD(IPDG/100,10)),RMASS(MOD(IPDG/10,10)))
+ & /(RMASS(MOD(IPDG/1000,10))+RMASS(MOD(IPDG/100,10))
+ & +RMASS(MOD(IPDG/10,10)))
+ 50 CALL HWDTHR(PHEP(1,MHEP),PHEP(1,NHEP-1),PHEP(1,NHEP-2),
+ & PHEP(1,NHEP),HWDWWT)
+ DOT1=HWULDO(PHEP(1,MHEP),PHEP(1,NHEP-1))
+ DOT2=HWULDO(PHEP(1,MHEP),PHEP(1,NHEP-2))
+ IF (DOT1*(WTMX-DOT1-XS*DOT2).LT.HWR()*WTMX2) GOTO 50
+ ELSE
+ CALL HWDTHR(PHEP(1,MHEP),PHEP(1,NHEP-2),PHEP(1,NHEP-1),
+ & PHEP(1,NHEP),HWDPWT)
+ ENDIF
+ ELSEIF (NPRODS(IM).EQ.4) THEN
+C 4-body decay
+ CALL HWDFOR(PHEP(1,MHEP ),PHEP(1,NHEP-3),PHEP(1,NHEP-2),
+ & PHEP(1,NHEP-1),PHEP(1,NHEP))
+ ELSEIF (NPRODS(IM).EQ.5) THEN
+C 5-body decay
+ CALL HWDFIV(PHEP(1,MHEP ),PHEP(1,NHEP-4),PHEP(1,NHEP-3),
+ & PHEP(1,NHEP-2),PHEP(1,NHEP-1),PHEP(1,NHEP))
+ ELSE
+ CALL HWWARN('HWDHAD',104,*999)
+ ENDIF
+ ENDIF
+ ENDIF
+ 100 CONTINUE
+C---MAY HAVE OVERFLOWED /HEPEVT/
+ CALL HWWARN('HWDHAD',105,*999)
+ 999 END
+CDECK ID>, HWDHGC.
+*CMZ :- -26/04/91 11.11.55 by Bryan Webber
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDHGC(TAU,FNREAL,FNIMAG)
+C-----------------------------------------------------------------------
+C CALCULATE THE COMPLEX FUNCTION F OF HHG eq 2.18
+C FOR USE IN H-->GAMMGAMM DECAYS
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION TAU,FNREAL,FNIMAG,FNLOG,FNSQR
+ IF (TAU.GT.ONE) THEN
+ FNREAL=(ASIN(1/SQRT(TAU)))**2
+ FNIMAG=0
+ ELSEIF (TAU.LT.ONE) THEN
+ FNSQR=SQRT(1-TAU)
+ FNLOG=LOG((1+FNSQR)/(1-FNSQR))
+ FNREAL=-0.25 * (FNLOG**2 - PIFAC**2)
+ FNIMAG= 0.5 * PIFAC*FNLOG
+ ELSE
+ FNREAL=0.25*PIFAC**2
+ FNIMAG=0
+ ENDIF
+ END
+CDECK ID>, HWDHGF.
+*CMZ :- -02/05/91 11.11.45 by Federico Carminati
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ FUNCTION HWDHGF(X,Y)
+C-----------------------------------------------------------------------
+C CALCULATE THE DOUBLE BREIT-WIGNER INTEGRAL
+C X=(EMV/EMH)**2 , Y=EMV*GAMV/EMH**2
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWDHGF,X,Y,CHANGE,X1,X2,FAC1,FAC2,TH1,TH2,TH1HI,
+ & TH1LO,TH2HI,TH2LO,X2MAX,SQFAC
+ INTEGER NBIN,IBIN1,IBIN2
+C CHANGE IS THE POINT WHERE DIRECT INTEGRATION BEGINS TO CONVERGE
+C FASTER THAN STANDARD BREIT-WIGNER SUBSTITUTION
+ DATA CHANGE,NBIN/0.425,25/
+ HWDHGF=0
+ IF (Y.LT.ZERO) RETURN
+ IF (X.GT.CHANGE) THEN
+C---DIRECT INTEGRATION
+ FAC1=0.25 / NBIN
+ DO 200 IBIN1=1,NBIN
+ X1=(IBIN1-0.5) * FAC1
+ FAC2=( (1-SQRT(X1))**2-X1 ) / NBIN
+ DO 100 IBIN2=1,NBIN
+ X2=(IBIN2-0.5) * FAC2 + X1
+ SQFAC=1+X1**2+X2**2-2*(X1+X2+X1*X2)
+ IF (SQFAC.LT.ZERO) GOTO 100
+ HWDHGF=HWDHGF + 2.
+ & * ((1-X1-X2)**2+8*X1*X2)
+ & * SQRT(SQFAC)
+ & / ((X1-X)**2+Y**2) *Y
+ & / ((X2-X)**2+Y**2) *Y
+ & * FAC1*FAC2
+ 100 CONTINUE
+ 200 CONTINUE
+ ELSE
+C---INTEGRATION USING TAN THETA SUBSTITUTIONS
+ TH1LO=ATAN((0-X)/Y)
+ TH1HI=ATAN((1-X)/Y)
+ FAC1=(TH1HI-TH1LO) / NBIN
+ DO 400 IBIN1=1,NBIN
+ TH1=(IBIN1-0.5) * FAC1 + TH1LO
+ X1=Y*TAN(TH1) + X
+ X2MAX=MIN(X1,(1-SQRT(X1))**2)
+ TH2LO=ATAN((0-X)/Y)
+ TH2HI=ATAN((X2MAX-X)/Y)
+ FAC2=(TH2HI-TH2LO) / NBIN
+ DO 300 IBIN2=1,NBIN
+ TH2=(IBIN2-0.5) * FAC2 + TH2LO
+ X2=Y*TAN(TH2) + X
+ SQFAC=1+X1**2+X2**2-2*(X1+X2+X1*X2)
+ IF (SQFAC.LT.ZERO) GOTO 300
+ HWDHGF=HWDHGF + 2.
+ & * ((1-X1-X2)**2+8*X1*X2)
+ & * SQRT(SQFAC)
+ & * FAC1 * FAC2
+ 300 CONTINUE
+ 400 CONTINUE
+ ENDIF
+ HWDHGF=HWDHGF/(PIFAC*PIFAC)
+ END
+CDECK ID>, HWDHIG.
+*CMZ :- -24/04/92 14.23.44 by Mike Seymour
+*-- Author : Mike Seymour
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDHIG(GAMINP)
+C-----------------------------------------------------------------------
+C HIGGS DECAY ROUTINE
+C A) FOR GAMinp=0 FIND AND DECAY HIGGS
+C B) FOR GAMinp>0 CALCULATE TOTAL HIGGS WIDTH
+C FOR EMH=GAMINP. STORE RESULT IN GAMINP.
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWDHGF,HWR,HWRUNI,HWUSQR,HWUPCM,GAMINP,EMH,
+ & EMF,COLFAC,ENF,K1,K0,BET0,BET1,GAM0,GAM1,SCLOG,CFAC,XF,EM,GAMLIM,
+ & GAM,XW,EMW,XZ,EMZ,YW,YZ,EMI,TAUT,TAUW,WIDHIG,VECDEC,EMB,GAMB,
+ & TMIN,TMAX1,EM1,TMAX2,EM2,X1,X2,PROB,PCM,SUMR,SUMI,TAUTR,TAUTI,
+ & TAUWR,TAUWI,GFACTR
+ INTEGER HWRINT,IHIG,I,IFERM,NLOOK,I1,I2,IPART,IMODE,IDEC,MMAX
+ LOGICAL HWRLOG
+ EXTERNAL HWDHGF,HWR,HWRUNI,HWUSQR,HWUPCM,HWRINT,HWRLOG
+ SAVE GAM,EM,VECDEC
+ PARAMETER (NLOOK=100)
+ DIMENSION VECDEC(2,0:NLOOK)
+ EQUIVALENCE (EMW,RMASS(198)),(EMZ,RMASS(200))
+ DATA GAMLIM,GAM,EM/10D0,2*0D0/
+C---IF DECAY, FIND HIGGS (HWDHAD WILL HAVE GIVEN IT STATUS=1)
+ IF (GAMINP.EQ.ZERO) THEN
+ IHIG=0
+ DO 10 I=1,NHEP
+ 10 IF (IHIG.EQ.0.AND.IDHW(I).EQ.201.AND.ISTHEP(I).EQ.1) IHIG=I
+ IF (IHIG.EQ.0) CALL HWWARN('HWDHIG',101,*999)
+ EMH=PHEP(5,IHIG)
+ IF (EMH.LE.ZERO) CALL HWWARN('HWDHIG',102,*999)
+ EMSCA=EMH
+ ELSE
+ EMH=GAMINP
+ IF (EMH.LE.ZERO) THEN
+ GAMINP=0
+ RETURN
+ ENDIF
+ ENDIF
+C---CALCULATE BRANCHING FRACTIONS
+C---FERMIONS
+C---NLL CORRECTION TO QUARK DECAY RATE (HHG eq 2.6-9)
+ ENF=0
+ DO 1 I=1,6
+ 1 IF (2*RMASS(I).LT.EMH) ENF=ENF+1
+ K1=5/PIFAC**2
+ K0=3/(4*PIFAC**2)
+ BET0=(11*CAFAC-2*ENF)/3
+ BET1=(34*CAFAC**2-(10*CAFAC+6*CFFAC)*ENF)/3
+ GAM0=-8
+ GAM1=-404./3+40*ENF/9
+ SCLOG=LOG(EMH**2/QCDLAM**2)
+ CFAC=1 + ( K1/K0 - 2*GAM0 + GAM0*BET1/BET0**2*LOG(SCLOG)
+ & + (GAM0*BET1-GAM1*BET0)/BET0**2) / (BET0*SCLOG)
+ DO 100 IFERM=1,9
+ IF (IFERM.LE.6) THEN
+ EMF=RMASS(IFERM)
+ XF=(EMF/EMH)**2
+ COLFAC=FLOAT(NCOLO)
+ IF (EMF.GT.QCDLAM)
+ & EMF=EMF*(LOG(EMH/QCDLAM)/LOG(EMF/QCDLAM))**(GAM0/(2*BET0))
+ ELSE
+ EMF=RMASS(107+IFERM*2)
+ XF=(EMF/EMH)**2
+ COLFAC=1
+ CFAC=1
+ ENDIF
+ IF (FOUR*XF.LT.ONE) THEN
+ GFACTR=ALPHEM/(8.*SWEIN*EMW**2)
+ BRHIG(IFERM)=COLFAC*GFACTR*EMH*EMF**2 * (1-4*XF)**1.5 * CFAC
+ ELSE
+ BRHIG(IFERM)=0
+ ENDIF
+ 100 CONTINUE
+C---W*W*/Z*Z*
+ IF (ABS(EM-EMH).GE.GAMLIM*GAM) THEN
+C---OFF EDGE OF LOOK-UP TABLE
+ XW=(EMW/EMH)**2
+ XZ=(EMZ/EMH)**2
+ YW=EMW*GAMW/EMH**2
+ YZ=EMZ*GAMZ/EMH**2
+ BRHIG(10)=.50*GFACTR * EMH**3 * HWDHGF(XW,YW)
+ BRHIG(11)=.25*GFACTR * EMH**3 * HWDHGF(XZ,YZ)
+ ELSE
+C---LOOK IT UP
+ EMI=((EMH-EM)/(GAM*GAMLIM)+1)*NLOOK/2.0
+ I1=INT(EMI)
+ I2=INT(EMI+1)
+ BRHIG(10)=.50*GFACTR * EMH**3 * ( VECDEC(1,I1)*(I2-EMI) +
+ & VECDEC(1,I2)*(EMI-I1) )
+ BRHIG(11)=.25*GFACTR * EMH**3 * ( VECDEC(2,I1)*(I2-EMI) +
+ & VECDEC(2,I2)*(EMI-I1) )
+ ENDIF
+C---GAMMAGAMMA
+ TAUT=(2*RMASS(6)/EMH)**2
+ TAUW=(2*EMW/EMH)**2
+ CALL HWDHGC(TAUT,TAUTR,TAUTI)
+ CALL HWDHGC(TAUW,TAUWR,TAUWI)
+ SUMR=4./3*( - 2*TAUT*( 1 + (1-TAUT)*TAUTR ) ) * ENHANC(6)
+ & +(2 + 3*TAUW*( 1 + (2-TAUW)*TAUWR ) ) * ENHANC(10)
+ SUMI=4./3*( - 2*TAUT*( (1-TAUT)*TAUTI ) ) * ENHANC(6)
+ & +( 3*TAUW*( (2-TAUW)*TAUWI ) ) * ENHANC(10)
+ BRHIG(12)=GFACTR*.03125*(ALPHEM/PIFAC)**2
+ & *EMH**3 * (SUMR**2 + SUMI**2)
+ WIDHIG=0
+ DO 200 IPART=1, 12
+ IF (IPART.LT.12) BRHIG(IPART)=BRHIG(IPART)*ENHANC(IPART)**2
+ 200 WIDHIG=WIDHIG+BRHIG(IPART)
+ IF (WIDHIG.EQ.ZERO) CALL HWWARN('HWDHIG',103,*999)
+ DO 300 IPART=1, 12
+ 300 BRHIG(IPART)=BRHIG(IPART)/WIDHIG
+ IF (EM.NE.RMASS(201)) THEN
+C---SET UP W*W*/Z*Z* LOOKUP TABLES
+ EM=EMH
+ GAM=WIDHIG
+ GAMLIM=MAX(GAMLIM,GAMMAX)
+ DO 400 I=0,NLOOK
+ EMH=(I*2.0/NLOOK-1)*GAM*GAMLIM+EM
+ XW=(EMW/EMH)**2
+ XZ=(EMZ/EMH)**2
+ YW=EMW*GAMW/EMH**2
+ YZ=EMZ*GAMZ/EMH**2
+ VECDEC(1,I)=HWDHGF(XW,YW)
+ VECDEC(2,I)=HWDHGF(XZ,YZ)
+ 400 CONTINUE
+ EMH=EM
+ ENDIF
+ IF (GAMINP.GT.ZERO) THEN
+ GAMINP=WIDHIG
+ RETURN
+ ENDIF
+C---SEE IF USER SPECIFIED A DECAY MODE
+ IMODE=MOD(IPROC,100)
+C---IF NOT, CHOOSE ONE
+ IF (IMODE.LT.1.OR.IMODE.GT.12) THEN
+ MMAX=12
+ IF (IMODE.LT.1) MMAX=6
+ 500 IMODE=HWRINT(1,MMAX)
+ IF (BRHIG(IMODE).LT.HWR()) GOTO 500
+ ENDIF
+C---SEE IF SPECIFIED DECAY IS POSSIBLE
+ IF (BRHIG(IMODE).EQ.ZERO) CALL HWWARN('HWDHIG',104,*999)
+ IF (IMODE.LE.6) THEN
+ IDEC=IMODE
+ ELSEIF (IMODE.LE.9) THEN
+ IDEC=107+IMODE*2
+ ELSEIF (IMODE.EQ.10) THEN
+ IDEC=198
+ ELSEIF (IMODE.EQ.11) THEN
+ IDEC=200
+ ELSEIF (IMODE.EQ.12) THEN
+ IDEC=59
+ ENDIF
+C---STATUS, IDs AND POINTERS
+ ISTHEP(IHIG)=195
+ DO 600 I=1,2
+ ISTHEP(NHEP+I)=193
+ IDHW(NHEP+I)=IDEC
+ IDHEP(NHEP+I)=IDPDG(IDEC)
+ JDAHEP(I,IHIG)=NHEP+I
+ JMOHEP(1,NHEP+I)=IHIG
+ JMOHEP(2,NHEP+I)=NHEP+(3-I)
+ JDAHEP(2,NHEP+I)=NHEP+(3-I)
+ PHEP(5,NHEP+I)=RMASS(IDEC)
+ IDEC=IDEC+6
+ IF (IDEC.EQ.204) IDEC=199
+ IF (IDEC.EQ.206) IDEC=200
+ IF (IDEC.EQ. 65) IDEC= 59
+ 600 CONTINUE
+C---ALLOW W/Z TO BE OFF-SHELL
+ IF (IMODE.EQ.10.OR.IMODE.EQ.11) THEN
+ IF (IMODE.EQ.10) THEN
+ EMB=EMW
+ GAMB=GAMW
+ ELSE
+ EMB=EMZ
+ GAMB=GAMZ
+ ENDIF
+C---STANDARD MASS DISTRIBUTION
+ 700 TMIN=ATAN(-EMB/GAMB)
+ TMAX1=ATAN((EMH**2/EMB-EMB)/GAMB)
+ EM1=HWUSQR(EMB*(GAMB*TAN(HWRUNI(0,TMIN,TMAX1))+EMB))
+ TMAX2=ATAN(((EMH-EM1)**2/EMB-EMB)/GAMB)
+ EM2=HWUSQR(EMB*(GAMB*TAN(HWRUNI(0,TMIN,TMAX2))+EMB))
+ X1=(EM1/EMH)**2
+ X2=(EM2/EMH)**2
+C---CORRECT MASS DISTRIBUTION
+ PROB=HWUSQR(1+X1**2+X2**2-2*X1-2*X2-2*X1*X2)
+ & * ((X1+X2-1)**2 + 8*X1*X2)
+ IF (.NOT.HWRLOG(PROB)) GOTO 700
+C---CALCULATE SPIN DENSITY MATRIX
+ RHOHEP(1,NHEP+1)=4*X1*X2 / (8*X1*X2 + (X1+X2-1)**2)
+ RHOHEP(2,NHEP+1)=(X1+X2-1)**2 / (8*X1*X2 + (X1+X2-1)**2)
+ RHOHEP(3,NHEP+1)=RHOHEP(1,NHEP+1)
+C---SYMMETRIZE DISTRIBUTIONS IN PARTICLES 1,2
+ IF (HWRLOG(HALF)) THEN
+ PHEP(5,NHEP+1)=EM1
+ PHEP(5,NHEP+2)=EM2
+ ELSE
+ PHEP(5,NHEP+1)=EM2
+ PHEP(5,NHEP+2)=EM1
+ ENDIF
+ ENDIF
+C---DO DECAY
+ PCM=HWUPCM(EMH,PHEP(5,NHEP+1),PHEP(5,NHEP+2))
+ IF (PCM.LT.ZERO) CALL HWWARN('HWDHIG',105,*999)
+ CALL HWDTWO(PHEP(1,IHIG),PHEP(1,NHEP+1),PHEP(1,NHEP+2),
+ & PCM,TWO,.TRUE.)
+ NHEP=NHEP+2
+C---IF QUARK DECAY, HADRONIZE
+ IF (IMODE.LE.6) THEN
+ ISTHEP(NHEP-1)=113
+ ISTHEP(NHEP)=114
+ CALL HWBGEN
+ CALL HWDHOB
+ CALL HWCFOR
+ CALL HWCDEC
+ ENDIF
+ 999 END
+CDECK ID>, HWDHOB.
+*CMZ :- -20/10/99 09:46:43 by Peter Richardson
+*-- Author : Ian Knowles & Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDHOB
+C-----------------------------------------------------------------------
+C Performs decays of heavy objects (heavy quarks & SUSY particles)
+C MODIFIED TO INCLUDE R-PARITY VIOLATING SUSY PR 9/4/99
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWUMBW,HWUPCM,HWR,SDKM,RN,BF,PCM,
+ & EMMX,EMWSQ,GMWSQ,EMLIM,PW(5),EMTST,HWDPWT,HWDWWT,HWULDO,PDW(5,3)
+ INTEGER IST(3),IHEP,IS,ID,IM,I,JHEP,KHEP,LHEP,MHEP,NPR,ISM,JCM,
+ & MTRY,NTRY,IDM,IDM2,THEP,CLSAVE(2),WHEP,RHEP
+ LOGICAL FOUND
+ EXTERNAL HWR,HWDPWT,HWDWWT
+ DATA IST/113,114,114/
+ IF (IERROR.NE.0) RETURN
+ 10 FOUND=.FALSE.
+ CLSAVE(1) = 0
+ CLSAVE(2) = 0
+ DO 60 IHEP=1,NMXHEP
+ IS=ISTHEP(IHEP)
+ ID=IDHW(IHEP)
+ IF (.NOT.RSTAB(ID).AND.(ID.EQ.6.OR.ID.EQ.12.OR.
+ & (ID.GE.203.AND.ID.LE.218).OR.ABS(IDPDG(ID)).GT.1000000).AND.
+ & (IS.EQ.190.OR.(IS.GE.147.AND.IS.LE.151))) THEN
+ FOUND=.TRUE.
+ IF(.NOT.RPARTY) THEN
+ NHEP = NHEP+1
+ ISTHEP(NHEP) = 3
+ IDHW(NHEP) = 20
+ IDHEP(NHEP) = 0
+ CALL HWVEQU(5,PHEP(1,IHEP),PHEP(1,NHEP))
+ CALL HWVEQU(4,VHEP(1,IHEP),VHEP(1,NHEP))
+ JMOHEP(1,NHEP)=JMOHEP(1,IHEP)
+ JMOHEP(2,NHEP)=JMOHEP(2,IHEP)
+ JDAHEP(1,NHEP)=JDAHEP(1,IHEP)
+ JDAHEP(2,NHEP)=JDAHEP(2,IHEP)
+ ENDIF
+C Make a copy of decaying object
+ NHEP=NHEP+1
+ ISTHEP(NHEP)=155
+ IDHW(NHEP)=IDHW(IHEP)
+ IDHEP(NHEP)=IDHEP(IHEP)
+ CALL HWVEQU(5,PHEP(1,IHEP),PHEP(1,NHEP))
+ CALL HWVEQU(4,VHEP(1,IHEP),VHEP(1,NHEP))
+ JMOHEP(1,NHEP)=JMOHEP(1,IHEP)
+ JMOHEP(2,NHEP)=JMOHEP(2,IHEP)
+ MTRY=0
+ 15 MTRY=MTRY+1
+C Select decay mode
+ RN=HWR()
+ BF=0.
+ IM=LSTRT(ID)
+ DO 20 I=1,NMODES(ID)
+ BF=BF+BRFRAC(IM)
+ IF (BF.GE.RN) GOTO 30
+ 20 IM=LNEXT(IM)
+ CALL HWWARN('HWDHOB',50,*30)
+ 30 IF (NHEP+5.GT.NMXHEP) CALL HWWARN('HWDHOB',100,*999)
+ NPR=NPRODS(IM)
+ JDAHEP(1,NHEP)=NHEP+1
+ JDAHEP(2,NHEP)=NHEP+NPR
+C Reset colour pointers (if set)
+ JHEP=JMOHEP(2,IHEP)
+ IF (JHEP.GT.0) THEN
+ IF (JDAHEP(2,JHEP).EQ.IHEP) JDAHEP(2,JHEP)=NHEP
+ IF(.NOT.RPARTY.AND.ISTHEP(JHEP).EQ.155
+ & .AND.ABS(IDHEP(JHEP)).GT.1000000
+ & .AND.JDAHEP(2,JHEP-1).EQ.IHEP) JDAHEP(2,JHEP-1) = NHEP
+ ENDIF
+ JHEP=JDAHEP(2,IHEP)
+ IF (JHEP.GT.0) THEN
+ IF (JMOHEP(2,JHEP).EQ.IHEP) JMOHEP(2,JHEP)=NHEP
+ IF(.NOT.RPARTY.AND.ISTHEP(JHEP).EQ.155
+ & .AND.ABS(IDHEP(JHEP)).GT.1000000
+ & .AND.JMOHEP(2,JHEP-1).EQ.IHEP) JMOHEP(2,JHEP-1) = NHEP
+ ENDIF
+C--Reset colour pointers if baryon number violated
+ IF(.NOT.RPARTY) THEN
+ DO JHEP=1,NHEP
+ IF(ISTHEP(JHEP).EQ.155
+ & .AND.ABS(IDHEP(JHEP)).GT.1000000.AND.
+ & JDAHEP(2,JHEP-1).EQ.IHEP) JDAHEP(2,JHEP-1)= NHEP
+ IF(JDAHEP(2,JHEP).EQ.IHEP) JDAHEP(2,JHEP)=NHEP
+ IF(JMOHEP(2,JHEP).EQ.IHEP) JMOHEP(2,JHEP)=NHEP
+ ENDDO
+ IF(HRDCOL(1,1).EQ.IHEP) HRDCOL(1,1)=NHEP
+ ENDIF
+C Relabel original track
+ ISTHEP(IHEP)=3
+ JMOHEP(2,IHEP)=JMOHEP(1,IHEP)
+ JDAHEP(1,IHEP)=NHEP
+ JDAHEP(2,IHEP)=NHEP
+C Label decay products and choose masses
+ LHEP=NHEP
+ MHEP=LHEP+1
+ NTRY=0
+ 35 NTRY=NTRY+1
+ SDKM=PHEP(5,NHEP)
+ DO 40 I=1,NPR
+ NHEP=NHEP+1
+ IDHW(NHEP)=IDKPRD(I,IM)
+ IDHEP(NHEP)=IDPDG(IDKPRD(I,IM))
+ ISTHEP(NHEP)=IST(I)
+ JMOHEP(1,NHEP)=LHEP
+ JDAHEP(1,NHEP)=0
+ PHEP(5,NHEP)=HWUMBW(IDKPRD(I,IM))
+ 40 SDKM=SDKM-PHEP(5,NHEP)
+ IF (SDKM.LT.ZERO) THEN
+ NHEP=NHEP-NPR
+ IF (NTRY.LE.NETRY) GO TO 35
+ CALL HWWARN('HWDHOB',1,*45)
+ 45 IF (MTRY.LE.NETRY) GO TO 15
+ CALL HWWARN('HWDHOB',101,*999)
+ ENDIF
+C Assign production vertices to decay products
+ CALL HWUDKL(ID,PHEP(1,IHEP),VHEP(1,MHEP))
+ CALL HWVSUM(4,VHEP(1,IHEP),VHEP(1,MHEP),VHEP(1,MHEP))
+ CALL HWVEQU(4,VHEP(1,MHEP),VHEP(1,NHEP))
+ IF (NPR.EQ.2) THEN
+C Two body decay: LHEP -> MHEP + NHEP
+ PCM=HWUPCM(PHEP(5,IHEP),PHEP(5,MHEP),PHEP(5,NHEP))
+ CALL HWDTWO(PHEP(1,IHEP),PHEP(1,MHEP),
+ & PHEP(1,NHEP),PCM,TWO,.FALSE.)
+ ELSEIF (NPR.EQ.3) THEN
+C Three body decay: LHEP -> KHEP + MHEP + NHEP
+ KHEP=MHEP
+ MHEP=MHEP+1
+C Provisional colour self-connection of KHEP
+ JMOHEP(2,KHEP)=KHEP
+ JDAHEP(2,KHEP)=KHEP
+ IF (NME(IM).EQ.100) THEN
+C Generate decay momenta using full (V-A)*(V-A) matrix element
+ EMMX=PHEP(5,IHEP)-PHEP(5,NHEP)
+ EMWSQ=RMASS(198)**2
+ GMWSQ=(RMASS(198)*GAMW)**2
+ EMLIM=GMWSQ
+ IF (EMMX.LT.RMASS(198)) EMLIM=EMLIM+(EMWSQ-EMMX**2)**2
+ 50 CALL HWDTHR(PHEP(1,IHEP),PHEP(1,MHEP),
+ & PHEP(1,KHEP),PHEP(1,NHEP),HWDWWT)
+ CALL HWVSUM(4,PHEP(1,KHEP),PHEP(1,MHEP),PW)
+ PW(5)=HWULDO(PW,PW)
+ EMTST=(EMWSQ-PW(5))**2
+ IF ((EMTST+GMWSQ)*HWR().GT.EMLIM) GOTO 50
+ PW(5)=SQRT(PW(5))
+C Assign production vertices to 1 and 2
+ CALL HWUDKL(198,PW,VHEP(1,KHEP))
+ CALL HWVSUM(4,VHEP(1,NHEP),VHEP(1,KHEP),VHEP(1,KHEP))
+ ELSEIF(NME(IM).EQ.300) THEN
+C Generate momenta using 3-body RPV matrix element
+ CALL HWDRME(LHEP,KHEP)
+ ELSE
+C Three body phase space decay
+ CALL HWDTHR(PHEP(1,IHEP),PHEP(1,MHEP),
+ & PHEP(1,KHEP),PHEP(1,NHEP),HWDPWT)
+ ENDIF
+ CALL HWVEQU(4,VHEP(1,KHEP),VHEP(1,MHEP))
+ ELSEIF(NPR.EQ.4) THEN
+C Four body decay: LHEP -> KHEP + RHEP + MHEP + NHEP
+ KHEP = MHEP
+ RHEP = MHEP+1
+ MHEP = MHEP+2
+C Provisional colour connections of KHEP and RHEP
+ JMOHEP(2,KHEP)=RHEP
+ JDAHEP(2,KHEP)=RHEP
+ JMOHEP(2,RHEP)=KHEP
+ JDAHEP(2,RHEP)=KHEP
+C Four body phase space decay
+ CALL HWDFOR(PHEP(1,IHEP),PHEP(1,KHEP),PHEP(1,RHEP),
+ & PHEP(1,MHEP),PHEP(1,NHEP))
+ CALL HWVEQU(4,VHEP(1,KHEP),VHEP(1,RHEP))
+ CALL HWVEQU(4,VHEP(1,KHEP),VHEP(1,MHEP))
+ ELSE
+ CALL HWWARN('HWDHOB',102,*999)
+ ENDIF
+C Colour connections
+ IF (ID.EQ.6.OR.ID.EQ.12.OR.(ID.GE.209.AND.ID.LE.212)
+ & .OR.(ID.GE.215.AND.ID.LE.218)) THEN
+ IF (NPR.EQ.3.AND.NME(IM).EQ.100) THEN
+C usual heavy quark decay
+ JMOHEP(2,KHEP)=MHEP
+ JDAHEP(2,KHEP)=MHEP
+ JMOHEP(2,MHEP)=KHEP
+ JDAHEP(2,MHEP)=KHEP
+ JMOHEP(2,NHEP)=LHEP
+ JDAHEP(2,NHEP)=LHEP
+ ELSEIF (ABS(IDHEP(MHEP)).EQ.37) THEN
+C heavy quark to charged Higgs
+ JMOHEP(2,MHEP)=MHEP
+ JDAHEP(2,MHEP)=MHEP
+ JMOHEP(2,NHEP)=LHEP
+ JDAHEP(2,NHEP)=LHEP
+ ELSEIF (ABS(IDHEP(NHEP)).EQ.37) THEN
+ JMOHEP(2,MHEP)=LHEP
+ JDAHEP(2,MHEP)=LHEP
+ JMOHEP(2,NHEP)=NHEP
+ JDAHEP(2,NHEP)=NHEP
+ ELSE
+ CALL HWWARN('HWDHOB',103,*999)
+ ENDIF
+ ELSE
+ IF(.NOT.RPARTY.AND.
+ & ((NPR.EQ.2.AND.ID.GE.401.AND.ID.LT.448.AND.
+ & IDHW(MHEP).LE.132.AND.IDHW(NHEP).LE.132)
+ & .OR.(NPR.EQ.3.AND.ID.GE.449.AND.ID.LE.457.AND.
+ & IDHW(MHEP).LE.132.AND.IDHW(NHEP).LE.132.AND.
+ & IDHW(MHEP-1).LE.132))) THEN
+C R-parity violating SUSY decays
+ IF(NPR.EQ.2) THEN
+C--Rparity slepton colour connections
+ IF(ID.GE.425.AND.ID.LE.448) THEN
+ IF(IDHW(MHEP).GT.12) THEN
+ JMOHEP(2,MHEP) = MHEP
+ JDAHEP(2,MHEP) = MHEP
+ JMOHEP(2,NHEP) = NHEP
+ JDAHEP(2,NHEP) = NHEP
+ ELSE
+ JMOHEP(2,MHEP) = NHEP
+ JDAHEP(2,MHEP) = NHEP
+ JMOHEP(2,NHEP) = MHEP
+ JDAHEP(2,NHEP) = MHEP
+ ENDIF
+C--Rparity squark colour connections
+ ELSE
+ IF(IDHEP(LHEP).GT.0) THEN
+C--LQD decay colour connections
+ IF(IDHW(MHEP).GT.12) THEN
+ JMOHEP(2,MHEP) = MHEP
+ JDAHEP(2,MHEP) = MHEP
+ JMOHEP(2,NHEP) = LHEP
+ JDAHEP(2,NHEP) = LHEP
+ ELSE
+C--UDD decay colour connections
+ HVFCEN = .TRUE.
+ CALL HWDRCL(LHEP,MHEP,CLSAVE)
+ ENDIF
+ ELSE
+C--Antisquark connections
+ IF(IDHW(MHEP).GT.12) THEN
+ JMOHEP(2,MHEP) = MHEP
+ JDAHEP(2,MHEP) = MHEP
+ JMOHEP(2,NHEP) = LHEP
+ JDAHEP(2,NHEP) = LHEP
+ ELSE
+ HVFCEN = .TRUE.
+ CALL HWDRCL(LHEP,MHEP,CLSAVE)
+ ENDIF
+ ENDIF
+ ENDIF
+ ELSE
+ IF(ID.GE.450.AND.ID.LE.457) THEN
+C--Rparity Neutralino/Chargino colour connection
+ IF(IDHW(MHEP-1).LE.12.AND.IDHW(MHEP).LE.12.
+ & AND.IDHW(NHEP).LE.12) THEN
+ HVFCEN = .TRUE.
+ CALL HWDRCL(LHEP,MHEP,CLSAVE)
+ ELSE
+ JMOHEP(2,MHEP) = NHEP
+ JDAHEP(2,MHEP) = NHEP
+ JMOHEP(2,NHEP) = MHEP
+ JDAHEP(2,NHEP) = MHEP
+ ENDIF
+C--Rparity gluino colour connections
+ ELSEIF(ID.EQ.449) THEN
+ IF(IDHW(MHEP-1).LE.12.AND.IDHW(MHEP).LE.12.
+ & AND.IDHW(NHEP).LE.12) THEN
+ HVFCEN = .TRUE.
+ CALL HWDRCL(LHEP,MHEP,CLSAVE)
+C--Now the lepton number violating decay
+ ELSE
+ IF(IDHW(MHEP).LE.6) THEN
+ JMOHEP(2,MHEP) = LHEP
+ JDAHEP(2,MHEP) = NHEP
+ JMOHEP(2,NHEP) = MHEP
+ JDAHEP(2,NHEP) = LHEP
+ ELSE
+ JMOHEP(2,MHEP) = NHEP
+ JDAHEP(2,MHEP) = LHEP
+ JMOHEP(2,NHEP) = LHEP
+ JDAHEP(2,NHEP) = MHEP
+ ENDIF
+ ENDIF
+ ELSE
+ CALL HWWARN('HWDHOB',104,*999)
+ ENDIF
+ ENDIF
+ ELSE
+C Normal SUSY decays
+ IF (ID.LE.448.AND.ID.GT.207) THEN
+C Squark (or slepton)
+ IF (IDHW(MHEP).EQ.449) THEN
+ IF (IDHEP(LHEP).GT.0) THEN
+ JMOHEP(2,MHEP)=LHEP
+ JDAHEP(2,MHEP)=NHEP
+ JMOHEP(2,NHEP)=MHEP
+ JDAHEP(2,NHEP)=LHEP
+ ELSE
+ JMOHEP(2,MHEP)=NHEP
+ JDAHEP(2,MHEP)=LHEP
+ JMOHEP(2,NHEP)=LHEP
+ JDAHEP(2,NHEP)=MHEP
+ ENDIF
+ ELSE
+ IF(NPR.EQ.3.AND.IDHW(MHEP).LE.12) THEN
+ JMOHEP(2,MHEP)=NHEP
+ JDAHEP(2,MHEP)=NHEP
+ JMOHEP(2,NHEP)=MHEP
+ JDAHEP(2,NHEP)=MHEP
+ ELSE
+ JMOHEP(2,MHEP)=MHEP
+ JDAHEP(2,MHEP)=MHEP
+ JMOHEP(2,NHEP)=LHEP
+ JDAHEP(2,NHEP)=LHEP
+ ENDIF
+ ENDIF
+ ELSEIF (ID.EQ.449) THEN
+C Gluino
+ IF (IDHW(NHEP).EQ.13) THEN
+ JMOHEP(2,MHEP)=MHEP
+ JDAHEP(2,MHEP)=MHEP
+ JMOHEP(2,NHEP)=LHEP
+ JDAHEP(2,NHEP)=LHEP
+ ELSEIF (IDHEP(MHEP).GT.0) THEN
+ JMOHEP(2,MHEP)=LHEP
+ JDAHEP(2,MHEP)=NHEP
+ JMOHEP(2,NHEP)=MHEP
+ JDAHEP(2,NHEP)=LHEP
+ ELSE
+ JMOHEP(2,MHEP)=NHEP
+ JDAHEP(2,MHEP)=LHEP
+ JMOHEP(2,NHEP)=LHEP
+ JDAHEP(2,NHEP)=MHEP
+ ENDIF
+ ELSE
+C Gaugino or Higgs
+ JMOHEP(2,MHEP)=NHEP
+ JDAHEP(2,MHEP)=NHEP
+ JMOHEP(2,NHEP)=MHEP
+ JDAHEP(2,NHEP)=MHEP
+ ENDIF
+ ENDIF
+ ENDIF
+C---SPECIAL CASE FOR THREE-BODY TOP DECAYS:
+C RELABEL THEM AS TWO TWO-BODY DECAYS FOR PARTON SHOWERING
+ IF ((ID.EQ.6.OR.ID.EQ.12).AND.NPR.EQ.3.AND.NME(IM).EQ.100) THEN
+C---STORE W DECAY PRODUCTS
+ CALL HWVEQU(10,PHEP(1,KHEP),PDW)
+C---BOOST THEM INTO W REST FRAME
+ CALL HWULOF(PW,PDW(1,1),PDW(1,3))
+C---REPLACE THEM BY W
+ CALL HWVEQU(5,PW,PHEP(1,KHEP))
+ WHEP=KHEP
+ IDHW(KHEP)=198
+ IF (ID.EQ.12) IDHW(KHEP)=199
+ IDHEP(KHEP)=IDPDG(IDHW(KHEP))
+ JMOHEP(2,KHEP)=KHEP
+ JDAHEP(2,KHEP)=KHEP
+ CALL HWVEQU(4,VHEP(1,NHEP),VHEP(1,KHEP))
+C---AND MOVE B UP
+ CALL HWVEQU(5,PHEP(1,NHEP),PHEP(1,MHEP))
+ IDHW(MHEP)=IDHW(NHEP)
+ IDHEP(MHEP)=IDHEP(NHEP)
+ JDAHEP(2,LHEP)=MHEP
+ JMOHEP(2,MHEP)=JMOHEP(2,NHEP)
+ JDAHEP(2,MHEP)=JDAHEP(2,NHEP)
+ CALL HWVEQU(4,VHEP(1,NHEP),VHEP(1,MHEP))
+ NHEP=MHEP
+C---DO PARTON SHOWER
+ EMSCA=PHEP(5,IHEP)
+ CALL HWBGEN
+ IF (IERROR.NE.0) RETURN
+C---FIND BOOSTED W MOMENTUM
+ NTRY=0
+ 41 NTRY=NTRY+1
+ IF (NTRY.GT.NHEP.OR.WHEP.LE.0.OR.WHEP.GT.NHEP)
+ $ CALL HWWARN('HWDHOB',101,*999)
+ WHEP=JDAHEP(1,WHEP)
+ IF (ISTHEP(WHEP).NE.190) GOTO 41
+C---AND HENCE ITS CHILDRENS MOMENTA
+ CALL HWULOB(PHEP(1,WHEP),PDW(1,3),PHEP(1,NHEP+1))
+ CALL HWVDIF(4,PHEP(1,WHEP),PHEP(1,NHEP+1),PHEP(1,NHEP+2))
+ PHEP(5,NHEP+2)=PDW(5,2)
+C---LABEL THEM
+ ISTHEP(WHEP)=195
+ DO 51 I=1,2
+ IDHW(NHEP+I)=IDKPRD(I,IM)
+ IDHEP(NHEP+I)=IDPDG(IDHW(NHEP+I))
+ ISTHEP(NHEP+I)=112+I
+ JDAHEP(I,WHEP)=NHEP+I
+ JMOHEP(1,NHEP+I)=WHEP
+ JMOHEP(2,NHEP+I)=NHEP+3-I
+ JDAHEP(2,NHEP+I)=NHEP+3-I
+ 51 CONTINUE
+ NHEP=NHEP+2
+C---ASSIGN PRODUCTION VERTICES TO 1 AND 2
+ CALL HWUDKL(198,PW,VHEP(1,NHEP))
+ CALL HWVSUM(4,VHEP(1,WHEP),VHEP(1,NHEP),VHEP(1,NHEP))
+ CALL HWVEQU(4,VHEP(1,NHEP),VHEP(1,NHEP-1))
+C---DO PARTON SHOWERS
+ EMSCA=PW(5)
+ CALL HWBGEN
+ IF (IERROR.NE.0) RETURN
+ ELSE
+C Do parton showers
+ EMSCA=PHEP(5,IHEP)
+ CALL HWBGEN
+ IF (IERROR.NE.0) RETURN
+ ENDIF
+ ENDIF
+C--New to correct colour connections in Rslash
+ IF(CLSAVE(1).NE.0) THEN
+ THEP = MHEP+1
+ ID = IDHW(CLSAVE(1))
+ IDM = IDHW(JMOHEP(1,CLSAVE(1)))
+ IDM2 = IDHW(LHEP)
+ IF(IDM.EQ.15) ID=IDHW(JMOHEP(1,JMOHEP(1,CLSAVE(1))))
+ IF((ID.LE.6.AND.((IDM.GE.419.AND.IDM.LE.424).OR.IDM.EQ.411.OR.
+ & IDM.EQ.412).
+ & AND.((IDM2.GE.413.AND.IDM2.LE.418)
+ & .OR.IDM2.EQ.449).OR.IDM2.EQ.405.OR.IDM2.EQ.406)
+ & .OR.(ID.LE.6.AND.IDM.EQ.449.AND.
+ & (((IDM2.GE.413.AND.IDM2.LE.418).OR.IDM2.EQ.405.OR.IDM2.EQ.406)
+ & .OR.IDM2.EQ.449)).OR.
+ & (IDM.EQ.15.AND.ID.LE.12.AND.ID.GE.7.AND.((IDM2.GE.413.AND.
+ & IDM2.LE.418).OR.IDM2.EQ.449.OR.IDM2.
+ & EQ.405.OR.IDM2.EQ.406))) THEN
+ IF(JMOHEP(2,CLSAVE(1)).EQ.MHEP) THEN
+ IF(IDHW(CLSAVE(1)).NE.13.AND.IDHW(CLSAVE(1)).NE.449)
+ & JMOHEP(2,CLSAVE(2)) = THEP
+ JDAHEP(2,MHEP) = CLSAVE(1)
+ JDAHEP(2,THEP) = CLSAVE(2)
+ ELSE
+ IF(IDHW(CLSAVE(1)).NE.13.AND.IDHW(CLSAVE(1)).NE.449)
+ & JMOHEP(2,CLSAVE(2)) = MHEP
+ JDAHEP(2,MHEP) = CLSAVE(2)
+ JDAHEP(2,THEP) = CLSAVE(1)
+ ENDIF
+ ELSEIF((ID.GT.6.AND.ID.LE.12.
+ & AND.((IDM.GE.413.AND.IDM.LE.418).OR.IDM.EQ.405.OR.
+ & IDM.EQ.406).AND.
+ & ((IDM2.GE.419.AND.IDM2.LE.424).OR.IDM2.EQ.449.OR.
+ & IDM2.EQ.411.OR.IDM2.EQ.412)).OR.
+ & (ID.GT.6.AND.ID.LE.12.AND.IDM.EQ.449.
+ & AND.((IDM2.GE.419.AND.IDM2.LE.424).OR.IDM2.EQ.449.OR.
+ & IDM2.EQ.411.OR.IDM2.EQ.412)).OR.
+ & (IDM.EQ.15.AND.ID.LE.6.AND.((IDM2.GE.419.AND.
+ & IDM2.LE.424).OR.IDM2.EQ.449.OR.IDM2.EQ.411.OR.
+ & IDM2.EQ.412))) THEN
+ IF(JDAHEP(2,CLSAVE(1)).EQ.MHEP) THEN
+ JDAHEP(2,CLSAVE(2))=THEP
+ JMOHEP(2,MHEP)=CLSAVE(1)
+ JMOHEP(2,THEP)=CLSAVE(2)
+ ELSE
+ JDAHEP(2,CLSAVE(2))=MHEP
+ JMOHEP(2,MHEP)=CLSAVE(2)
+ JMOHEP(2,THEP)=CLSAVE(1)
+ ENDIF
+ ENDIF
+ COLUPD = .FALSE.
+ CALL HWBCON
+ ENDIF
+ IF (IHEP.EQ.NHEP) GOTO 70
+ 60 CONTINUE
+ 70 IF (FOUND) THEN
+C Fix any SUSY colour disconnections
+ DO 80 IHEP=1,NHEP
+ IF (ISTHEP(IHEP).GE.147.AND.ISTHEP(IHEP).LE.151
+ & .AND.JDAHEP(2,IHEP).EQ.0) THEN
+ IM=JMOHEP(1,IHEP)
+C Chase connection back through SUSY decays
+ 75 IM=JMOHEP(1,IM)
+ ISM=ISTHEP(IM)
+ IF (ISM.EQ.120) GOTO 80
+ IF (ISM.NE.123.AND.ISM.NE.124.AND.ISM.NE.155) GOTO 75
+C Look for unclustered parton to connect
+ DO JHEP=1,NHEP
+ IF (ISTHEP(JHEP).GE.147.AND.ISTHEP(JHEP).LE.151) THEN
+ JCM=JMOHEP(2,JHEP)
+ IF (JCM.EQ.IM) THEN
+C Found it: connect
+ JMOHEP(2,JHEP)=IHEP
+ JDAHEP(2,IHEP)=JHEP
+ GOTO 80
+ ENDIF
+ ENDIF
+ ENDDO
+C Not found: need to go further back
+ GOTO 75
+ ENDIF
+ 80 CONTINUE
+C Go back to check for further heavy decay products
+ GOTO 10
+ ENDIF
+ 999 END
+CDECK ID>, HWDHVY.
+*CMZ :- -26/04/91 12.19.24 by Federico Carminati
+*-- Author : Ian Knowles & Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDHVY
+C-----------------------------------------------------------------------
+C Performs partonic decays of hadrons containing heavy quark(s):
+C either, meson/baryon spectator model weak decays;
+C or, quarkonia -> 2-gluons, q-qbar, 3-gluons, or 2-gluons + photon.
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION HWULDO,HWR,XS,XB,EMWSQ,GMWSQ,EMLIM,PW(4),
+ & EMTST,X1,X2,X3,TEST,HWDWWT,HWDPWT
+ INTEGER IST(3),I,IHEP,IM,ID,IDQ,IQ,IS,J
+ EXTERNAL HWR,HWDWWT,HWDPWT,HWULDO
+ DATA IST/113,114,114/
+ IF (IERROR.NE.0) RETURN
+ DO 100 I=1,NMXQDK
+ IF (I.GT.NQDK) THEN
+ NQDK=0
+ RETURN
+ ENDIF
+ IHEP=LOCQ(I)
+ IF (ISTHEP(IHEP).EQ.199) GOTO 100
+ IM=IMQDK(I)
+ IF (NHEP+NPRODS(IM).GT.NMXHEP) CALL HWWARN('HWDHVY',100,*999)
+ IF (IDKPRD(4,IM).NE.0) THEN
+C Weak decay of meson or baryon
+C Idenitify decaying heavy quark and spectator
+ ID=IDHW(IHEP)
+ IF (ID.EQ.136.OR.ID.EQ.140.OR.ID.EQ.144.OR.
+ & ID.EQ.150.OR.ID.EQ.155.OR.ID.EQ.158.OR.ID.EQ.161.OR.
+ & (ID.EQ.254.AND.IDKPRD(4,IM).EQ.11)) THEN
+C c hadron or c decay of B_c+
+ IDQ=4
+ IQ=NHEP+1
+ IS=NHEP+2
+ ELSEIF (ID.EQ.171.OR.ID.EQ.175.OR.ID.EQ.179.OR.
+ & ID.EQ.185.OR.ID.EQ.190.OR.ID.EQ.194.OR.ID.EQ.196.OR.
+ & (ID.EQ.230.AND.IDKPRD(4,IM).EQ.5)) THEN
+C cbar hadron or cbar decay of B_c-
+ IDQ=10
+ IS=NHEP+1
+ IQ=NHEP+2
+ ELSEIF ((ID.GE.221.AND.ID.LE.229).OR.
+ & (ID.EQ.230.AND.IDKPRD(4,IM).EQ.10)) THEN
+C b hadron or b decay of B_c-
+ IDQ=5
+ IQ=NHEP+1
+ IS=NHEP+2
+ ELSEIF ((ID.GE.245.AND.ID.LE.253).OR.
+ & (ID.EQ.254.AND.IDKPRD(4,IM).EQ.4)) THEN
+C bbar hadron or bbar decay of B_c+
+ IDQ=11
+ IS=NHEP+1
+ IQ=NHEP+2
+ ELSE
+C Decay not recognized
+ CALL HWWARN('HWDHVY',101,*999)
+ ENDIF
+C Label constituents
+ IF (NHEP+5.GT.NMXHEP) CALL HWWARN('HWDHVY',102,*999)
+ ISTHEP(IHEP)=199
+ JDAHEP(1,IHEP)=NHEP+1
+ JDAHEP(2,IHEP)=NHEP+2
+ IDHW(IQ)=IDQ
+ IDHW(IS)=IDKPRD(4,IM)
+ IDHEP(IQ)=IDPDG(IDQ)
+ IDHEP(IS)=IDPDG(IDKPRD(4,IM))
+ ISTHEP(IQ)=155
+ ISTHEP(IS)=115
+ JMOHEP(1,IQ)=IHEP
+ JMOHEP(2,IQ)=IS
+ JDAHEP(1,IQ)=NHEP+3
+ JDAHEP(2,IQ)=NHEP+5
+ JMOHEP(1,IS)=IHEP
+ JMOHEP(2,IS)=NHEP+5
+ JDAHEP(1,IS)=0
+ JDAHEP(2,IS)=NHEP+5
+ NHEP=NHEP+2
+C and weak decay product jets
+ DO 10 J=1,3
+ NHEP=NHEP+1
+ IDHW(NHEP)=IDKPRD(J,IM)
+ IDHEP(NHEP)=IDPDG(IDKPRD(J,IM))
+ ISTHEP(NHEP)=IST(J)
+ JMOHEP(1,NHEP)=IQ
+ JDAHEP(1,NHEP)=0
+ 10 PHEP(5,NHEP)=RMASS(IDKPRD(J,IM))
+ JMOHEP(2,NHEP-2)=NHEP-1
+ JDAHEP(2,NHEP-2)=NHEP-1
+ JMOHEP(2,NHEP-1)=NHEP-2
+ JDAHEP(2,NHEP-1)=NHEP-2
+ JMOHEP(2,NHEP )=IQ
+ JDAHEP(2,NHEP )=IQ
+C Share momenta in ratio of masses, preserving specator mass
+ XS=RMASS(IDHW(IS))/PHEP(5,IHEP)
+ XB=ONE-XS
+ CALL HWVSCA(5,XB,PHEP(1,IHEP),PHEP(1,IQ))
+ CALL HWVSCA(5,XS,PHEP(1,IHEP),PHEP(1,IS))
+ IF (NME(IM).EQ.100) THEN
+C Generate decay momenta using full (V-A)*(V-A) matrix element
+ EMWSQ=RMASS(198)**2
+ GMWSQ=(RMASS(198)*GAMW)**2
+ EMLIM=GMWSQ+(EMWSQ-(PHEP(5,IQ)-PHEP(5,NHEP))**2)**2
+ 20 CALL HWDTHR(PHEP(1,IQ ),PHEP(1,NHEP-1),
+ & PHEP(1,NHEP-2),PHEP(1,NHEP),HWDWWT)
+ CALL HWVSUM(4,PHEP(1,NHEP-2),PHEP(1,NHEP-1),PW)
+ EMTST=(HWULDO(PW,PW)-EMWSQ)**2
+ IF ((EMTST+GMWSQ)*HWR().GT.EMLIM) GOTO 20
+ ELSE
+C Use phase space
+ CALL HWDTHR(PHEP(1,IQ ),PHEP(1,NHEP-2),
+ & PHEP(1,NHEP-1),PHEP(1,NHEP),HWDPWT)
+ CALL HWVSUM(4,PHEP(1,NHEP-2),PHEP(1,NHEP-1),PW)
+ ENDIF
+C Set up production vertices
+ CALL HWVZRO(4,VHEP(1,IQ))
+ CALL HWVEQU(4,VHEP(1,IQ),VHEP(1,IS))
+ CALL HWVEQU(4,VHEP(1,IQ),VHEP(1,NHEP))
+ CALL HWUDKL(198,PW,VHEP(1,NHEP-2))
+ CALL HWVSUM(4,VHEP(1,IQ),VHEP(1,NHEP-2),VHEP(1,NHEP-2))
+ CALL HWVEQU(4,VHEP(1,NHEP-2),VHEP(1,NHEP-1))
+ EMSCA=PHEP(5,IQ)
+ ELSE
+C Quarkonium decay
+C Label products
+ ISTHEP(IHEP)=199
+ JDAHEP(1,IHEP)=NHEP+1
+ DO 30 J=1,NPRODS(IM)
+ NHEP=NHEP+1
+ IDHW(NHEP)=IDKPRD(J,IM)
+ IDHEP(NHEP)=IDPDG(IDKPRD(J,IM))
+ ISTHEP(NHEP)=IST(J)
+ JMOHEP(1,NHEP)=IHEP
+ JDAHEP(1,NHEP)=0
+ PHEP(5,NHEP)=RMASS(IDKPRD(J,IM))
+ 30 CALL HWVZRO(4,VHEP(1,NHEP))
+ JDAHEP(2,IHEP)=NHEP
+C Establish colour connections and select momentum configuration
+ IF (NPRODS(IM).EQ.3) THEN
+ IF (IDKPRD(3,IM).EQ.13) THEN
+C 3-gluon decay
+ JMOHEP(2,NHEP-2)=NHEP
+ JMOHEP(2,NHEP-1)=NHEP-2
+ JMOHEP(2,NHEP )=NHEP-1
+ JDAHEP(2,NHEP-2)=NHEP-1
+ JDAHEP(2,NHEP-1)=NHEP
+ JDAHEP(2,NHEP )=NHEP-2
+ ELSE
+C or 2-gluon + photon decay
+ JMOHEP(2,NHEP-2)=NHEP-1
+ JMOHEP(2,NHEP-1)=NHEP-2
+ JMOHEP(2,NHEP )=NHEP
+ JDAHEP(2,NHEP-2)=NHEP-1
+ JDAHEP(2,NHEP-1)=NHEP-2
+ JDAHEP(2,NHEP )=NHEP
+ ENDIF
+ IF (NME(IM).EQ.130) THEN
+C Use Ore & Powell orthopositronium matrix element
+ 40 CALL HWDTHR(PHEP(1,IHEP),PHEP(1,NHEP-2),
+ & PHEP(1,NHEP-1),PHEP(1,NHEP),HWDPWT)
+ X1=TWO*HWULDO(PHEP(1,IHEP),PHEP(1,NHEP-2))/PHEP(5,IHEP)**2
+ X2=TWO*HWULDO(PHEP(1,IHEP),PHEP(1,NHEP-1))/PHEP(5,IHEP)**2
+ X3=TWO-X1-X2
+ TEST=((X1*(ONE-X1))**2+(X2*(ONE-X2))**2+(X3*(ONE-X3))**2)
+ & /(X1*X2*X3)**2
+ IF (TEST.LT.TWO*HWR()) GOTO 40
+ ELSE
+C Use phase space
+ CALL HWDTHR(PHEP(1,IHEP),PHEP(1,NHEP-2),
+ & PHEP(1,NHEP-1),PHEP(1,NHEP),HWDPWT)
+ ENDIF
+ ELSE
+C Parapositronium 2-gluon or q-qbar decay
+ JMOHEP(2,NHEP-1)=NHEP
+ JMOHEP(2,NHEP )=NHEP-1
+ JDAHEP(2,NHEP-1)=NHEP
+ JDAHEP(2,NHEP )=NHEP-1
+ CALL HWDTWO(PHEP(1,IHEP),PHEP(1,NHEP-1),
+ & PHEP(1,NHEP),CMMOM(IM),TWO,.FALSE.)
+ ENDIF
+ EMSCA=PHEP(5,IHEP)
+ ENDIF
+C Process this new hard scatter
+ CALL HWVEQU(4,VTXQDK(1,I),VTXPIP)
+ CALL HWBGEN
+ CALL HWCFOR
+ CALL HWCDEC
+ CALL HWDHAD
+ 100 CONTINUE
+ NQDK=0
+ 999 END
+CDECK ID>, HWDRCL.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDRCL(IHEP,MHEP,CLSAVE)
+C-----------------------------------------------------------------------
+C Sets the colour connections in Baryon number violating decays
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ INTEGER IHEP,MHEP,ID,ID2,IDM2,IDM3,COLCON(2,2,3),FLACON(2,3),JHEP,
+ & DECAY,COLANT,KHEP,IDM,IDMB,IDMB2,IDMB3,IDMB4,QHEP,IDM4,
+ & CLSAVE(2),XHEP,I,HWRINT,THEP
+ LOGICAL CONBV
+C--Colour connections for the decays
+ DATA COLCON/-1,1,-1,-2,-2,1,-3,-1,-1,1,-2,-1/
+ DATA FLACON/1,-1,1,-1,-1,0/
+C--identify the decay
+ IF(IERROR.NE.0) RETURN
+ ID = IDHW(IHEP)
+ ID2 = IDHW(MHEP)
+ IF(ID.GE.450.AND.ID.LE.457) THEN
+ DECAY = 1
+ ELSEIF(ID.EQ.449) THEN
+ DECAY = 2
+ ELSEIF((ID.GE.411.AND.ID.LE.424).OR.ID.EQ.405.OR.ID.EQ.406) THEN
+ DECAY = 3
+ ELSE
+C--UNKNOWN DECAY
+ CALL HWWARN('HWDRCL',100,*999)
+ ENDIF
+ COLANT = 1
+C--identify the colour partner
+ IF(DECAY.GT.1.AND.ID2.LE.6) THEN
+C--colour partner
+ COLANT = 2
+ KHEP = JDAHEP(2,IHEP-1)
+ ELSEIF(DECAY.GT.1.AND.ID2.GE.7) THEN
+C--anticolour partner
+ COLANT = 3
+ KHEP = JMOHEP(2,IHEP)
+ ELSE
+ KHEP=IHEP
+ ENDIF
+ IDM = IDHW(JMOHEP(1,KHEP))
+ IF(ABS(IDPDG(IDM)).GT.1000000.OR.IDM.EQ.15) THEN
+ IDM2 = IDHW(JDAHEP(1,JMOHEP(1,KHEP)))
+ IDM3 = IDHW(JDAHEP(2,JMOHEP(1,KHEP)))
+ IDM4 = IDHW(JDAHEP(2,JMOHEP(1,KHEP))-1)
+ QHEP = JMOHEP(1,KHEP)
+ IDMB = IDHW(JMOHEP(1,QHEP))
+ IDMB2 = IDHW(JMOHEP(2,QHEP))
+ IDMB3 = IDHW(JDAHEP(1,QHEP))
+ IDMB4 = IDHW(JDAHEP(2,QHEP))
+ ENDIF
+C--Now decide if the colour partner decayed via BV
+ IF(COLANT.EQ.2.AND.((((IDM.GE.413.AND.IDM.LE.418).OR.
+ & IDM.EQ.449.OR.IDM.EQ.405.OR.IDM.EQ.406).AND.
+ & (IDM2.GE.7.AND.IDM2.LE.12.AND.
+ & IDM3.GE.7.AND.IDM3.LE.12.AND.
+ & IDM4.GE.7.AND.IDM4.LE.12)).OR.
+ & (IDM.EQ.15.AND.IDMB.LE.6.AND.IDMB2.LE.6.AND.
+ & ((IDMB3.GE.7.AND.IDMB4.GE.12.AND.IDMB4.EQ.449).OR.
+ & (IDMB3.GE.198.AND.IDMB3.LE.207.AND.
+ & ABS(IDPDG(IDMB4)).GT.1000000))))) THEN
+ CONBV = .TRUE.
+ COLUPD = .TRUE.
+ HVFCEN = .FALSE.
+ XHEP = JMOHEP(2,JDAHEP(2,JMOHEP(1,KHEP)))
+ ELSEIF(COLANT.EQ.3.AND.((((IDM.GE.419.AND.IDM.LE.424).OR.
+ & IDM.EQ.449.OR.IDM.EQ.411.OR.IDM.EQ.412).AND.
+ & (IDM2.LE.6.AND.IDM3.LE.6.AND.IDM4.LE.6)).OR.
+ & (IDM.EQ.15.AND.IDMB.GE.7.AND.IDMB.LE.12.AND.
+ & IDMB2.GE.7.AND.IDMB2.LE.12.AND.((IDMB3.LE.6.AND.
+ & IDMB4.EQ.449).OR.(ABS(IDPDG(IDMB4)).GT.1000000
+ & .AND.IDMB3.GE.198.AND.IDMB3.LE.207))))) THEN
+ CONBV = .TRUE.
+ COLUPD = .TRUE.
+ HVFCEN = .FALSE.
+ XHEP = JDAHEP(2,JDAHEP(2,JMOHEP(1,KHEP)))
+ ELSE
+ CONBV = .FALSE.
+ COLUPD = .FALSE.
+ XHEP = 0
+ ENDIF
+ IF(CONBV) THEN
+ IF(IDM.NE.15) THEN
+ CLSAVE(1) = JDAHEP(2,JMOHEP(1,KHEP))-1
+ CLSAVE(2) = CLSAVE(1)+1
+ ELSE
+ IF(IDMB4.EQ.449) THEN
+ DO I=1,2
+ CLSAVE(I) = JMOHEP(I,JMOHEP(1,KHEP))
+ IF(CLSAVE(I).EQ.XHEP) CLSAVE(I)=JDAHEP(1,JMOHEP(1,KHEP))
+ ENDDO
+ ELSE
+ CLSAVE(1) = JMOHEP(1,JMOHEP(1,KHEP))
+ CLSAVE(2) = JMOHEP(2,JMOHEP(1,KHEP))
+ ENDIF
+ ENDIF
+ ELSE
+ CLSAVE(1)=0
+ CLSAVE(2)=0
+ ENDIF
+C--Now set the colours for angular ordering
+ THEP = MHEP-1
+ IF(DECAY.EQ.1) THEN
+ IF(ID2.LE.6) THEN
+ JMOHEP(2,THEP) = THEP+HWRINT(1,2)
+ JDAHEP(2,THEP) = THEP
+ ELSE
+ JMOHEP(2,THEP) = THEP
+ JDAHEP(2,THEP) = THEP+HWRINT(1,2)
+ ENDIF
+ ELSEIF(DECAY.EQ.2) THEN
+ IF(ID2.LE.6) THEN
+ JMOHEP(2,THEP) = IHEP
+ JDAHEP(2,THEP) = THEP
+ ELSE
+ JMOHEP(2,THEP) = THEP
+ JDAHEP(2,THEP) = IHEP
+ ENDIF
+ ENDIF
+C--Colour of the second two
+ DO JHEP=1,2
+ IF(ID2.LE.6) THEN
+ JMOHEP(2,MHEP+JHEP-1) = MHEP+JHEP-1+
+ & COLCON(HWRINT(1,2),JHEP,DECAY)
+ JDAHEP(2,MHEP+JHEP-1) = MHEP+JHEP-1+FLACON(JHEP,DECAY)
+ ELSE
+ JDAHEP(2,MHEP+JHEP-1) = MHEP+JHEP-1+
+ & COLCON(HWRINT(1,2),JHEP,DECAY)
+ JMOHEP(2,MHEP+JHEP-1) = MHEP+JHEP-1+FLACON(JHEP,DECAY)
+ ENDIF
+ ENDDO
+C--Now set the colours of the colour partner
+ IF(DECAY.GT.1.AND..NOT.CONBV) THEN
+ IF(ID2.LE.6) JMOHEP(2,KHEP) = MHEP+HWRINT(0,1)
+ IF(ID2.GE.7) JDAHEP(2,KHEP) = MHEP+HWRINT(0,1)
+ ELSEIF(CONBV) THEN
+ IF(ID2.GT.6) THEN
+ JMOHEP(2,CLSAVE(1)) = MHEP+HWRINT(0,1)
+ IF(JMOHEP(2,CLSAVE(1)).EQ.MHEP) THEN
+ JMOHEP(2,CLSAVE(2)) = MHEP+1
+ ELSE
+ JMOHEP(2,CLSAVE(2)) = MHEP
+ ENDIF
+ ELSE
+ JDAHEP(2,CLSAVE(1)) = MHEP+HWRINT(0,1)
+ IF(JDAHEP(2,CLSAVE(1)).EQ.MHEP) THEN
+ JDAHEP(2,CLSAVE(2)) = MHEP+1
+ ELSE
+ JDAHEP(2,CLSAVE(2)) = MHEP
+ ENDIF
+ ENDIF
+ ENDIF
+ 999 END
+CDECK ID>, HWDRME.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDRME(LHEP,MHEP)
+C-----------------------------------------------------------------------
+C SUBROUTINE TO IMPLEMENT ALL RPARITY DECAY MATRIX ELEMENTS
+C-----------------------------------------------------------------------
+ INCLUDE 'HERWIG61.INC'
+ DOUBLE PRECISION SM(6),SW(6),HWULDO,INFCOL,AM, M12SQ,M23SQ,MSGN,
+ & M13SQ,A(6),B(6),SWEAK,MW,DECMOM(5),TEST(4),EPS,
+ & M12SQT(6),M23SQT(6),M13SQT(6),LIMIT,M(4),RAND,
+ & MC(2),MX2(6),MX(6),HWDPWT,HWR,HWDRM1,LAMD(3)
+ EXTERNAL HWDRM1,HWULDO,HWDPWT,HWR
+ INTEGER K,SN(3),LHEP,CSP,I,SB(3),J,ND,LTRY,MHEP,NSP,ID(3),IG,
+ & IDHWTP,IDHPTP,MTRY
+ PARAMETER(EPS=1D-20)
+ IF(IERROR.NE.0) RETURN
+C--Electroweak parameters, etc
+ SWEAK = SQRT(SWEIN)
+ MW = RMASS(198)
+ M(4) = PHEP(5,LHEP)
+ IG = IDHW(LHEP)
+C--Find the masses of the final state and zero parameters
+ DO K=1,3
+ ID(K) = IDHW(MHEP+K-1)
+ IF(ID(K).LE.12) THEN
+ SN(K)=ID(K)
+ ELSE
+ SN(K)=ID(K)-120
+ ENDIF
+ IF(SN(K).GT.6) SN(K)=SN(K)-6
+ M(K) = PHEP(5,LHEP+K)
+ SB(K)=SN(K)
+ LAMD(K) = ZERO
+ ENDDO
+ DO J=1,6
+ MX2(J) = ZERO
+ MX(J) = ZERO
+ M13SQT(J) = ZERO
+ M23SQT(J) = ZERO
+ M12SQT(J) = ZERO
+ ENDDO
+C--Evaluate the coefficents for the mode we want
+ IF(IG.GE.450.AND.IG.LE.453) THEN
+C--NEUTRALINO
+ NSP = IG-449
+ AM = RMASS(IG)
+ MSGN = ZSGNSS(NSP)
+ MC(1) = ZMIXSS(NSP,3)/(2*MW*COSB*SWEAK)
+ MC(2) = ZMIXSS(NSP,4)/(2*MW*SINB*SWEAK)
+C--Calculate the combinations of couplings needed
+ IF(ID(1).LE.12.AND.ID(2).LE.12.AND.ID(3).LE.12) THEN
+C--first for the UDD modes
+ DO J=1,2
+ A(J) = M(1)*MC(2)*QMIXSS(SN(1),2,J)
+ & +SLFCH(SN(1),NSP)*QMIXSS(SN(1),1,J)
+ B(J) = MSGN*(M(1)*MC(2)*QMIXSS(SN(1),1,J)
+ & +SRFCH(SN(1),NSP)*QMIXSS(SN(1),2,J))
+ MX2(J) = QMIXSS(SN(1),2,J)
+ A(J+2) = M(2)*MC(1)*QMIXSS(SN(2),2,J)
+ & +SLFCH(SN(2),NSP)*QMIXSS(SN(2),1,J)
+ B(J+2) = MSGN*(M(2)*MC(1)*QMIXSS(SN(2),1,J)
+ & +SRFCH(SN(2),NSP)*QMIXSS(SN(2),2,J))
+ MX2(J+2) = QMIXSS(SN(2),2,J)
+ A(J+4) = M(3)*MC(1)*QMIXSS(SN(3),2,J)
+ & +SLFCH(SN(3),NSP)*QMIXSS(SN(3),1,J)
+ B(J+4) = MSGN*(M(3)*MC(1)*QMIXSS(SN(3),1,J)
+ & +SRFCH(SN(3),NSP)*QMIXSS(SN(3),2,J))
+ MX2(J+2) = QMIXSS(SN(3),2,J)
+ ENDDO
+ DO K=1,3
+ SN(K) = SN(K)+400
+ SB(K) = SB(K)+412
+ ENDDO
+ ELSEIF(ID(1).GE.121.AND.ID(2).GE.121.AND.ID(3).GE.121) THEN
+C--Now for the LLE modes
+ DO J=1,2
+ A(J) = MSGN*(M(1)*MC(1)*LMIXSS(SN(1),1,J)
+ & +SRFCH(10+SN(1),NSP)*LMIXSS(SN(1),2,J))
+ B(J) = M(1)*MC(1)*LMIXSS(SN(1),2,J)
+ & +SLFCH(10+SN(1),NSP)*LMIXSS(SN(2),1,J)
+ MX2(J)= LMIXSS(SN(1),1,J)
+ A(J+2) = ZERO
+ B(J+2) = SLFCH(10+SN(2),NSP)*LMIXSS(SN(2),1,J)
+ MX2(J+2) = LMIXSS(SN(2),1,J)
+ A(J+4) = M(3)*MC(1)*LMIXSS(SN(3),2,J)
+ & +SLFCH(10+SN(3),NSP)*LMIXSS(SN(3),1,J)
+ B(J+4) = MSGN*(M(3)*MC(1)*LMIXSS(SN(3),1,J)
+ & +SRFCH(10+SN(3),NSP)*LMIXSS(SN(3),2,J))
+ MX2(4+J) = LMIXSS(SN(3),2,J)
+ ENDDO
+ DO J=1,3
+ SN(J) = SN(J) + 424
+ SB(J) = SB(J) + 436
+ ENDDO
+ ELSE
+C--Now for both types of LQD modes
+ IF(MOD(SN(1),2).EQ.0) THEN
+C--First the neutrino,down,antidown mode
+ DO J=1,2
+ A(J) = ZERO
+ B(J) = SLFCH(10+SN(1),NSP)*
+ & LMIXSS(SN(1),1,J)
+ MX2(J) = LMIXSS(SN(1),1,J)
+ A(J+2) = MSGN*(M(2)*MC(1)*QMIXSS(SN(2),1,J)
+ & +SRFCH(SN(2),NSP)*QMIXSS(SN(2),2,J))
+ B(J+2) = M(2)*MC(1)*QMIXSS(SN(2),2,J)
+ & +SLFCH(SN(2),NSP)*QMIXSS(SN(2),1,J)
+ MX2(2+J) = QMIXSS(SN(2),1,J)
+ A(J+4) = M(3)*MC(1)*QMIXSS(SN(3),2,J)
+ & +SLFCH(SN(3),NSP)*QMIXSS(SN(3),1,J)
+ B(J+4) = MSGN*(M(3)*MC(1)*QMIXSS(SN(3),1,J)
+ & +SRFCH(SN(3),NSP)*QMIXSS(SN(3),2,J))
+ MX2(J+4) = QMIXSS(SN(3),2,J)
+ ENDDO
+ ELSE
+C--Now the charged lepton, antiup,down modes
+ DO J=1,2
+ A(J) = MSGN*(M(1)*MC(1)*LMIXSS(SN(1),1,J)
+ & +SRFCH(10+SN(1),NSP)*LMIXSS(SN(1),2,J))
+ B(J) = M(1)*MC(1)*LMIXSS(SN(1),2,J)
+ & +SLFCH(10+SN(1),NSP)*LMIXSS(SN(1),1,J)
+ MX2(J) = LMIXSS(SN(1),1,J)
+ A(J+2) =MSGN*(M(2)*MC(2)*QMIXSS(SN(2),1,J)
+ & +SRFCH(SN(2),NSP)*QMIXSS(SN(2),2,J))
+ B(J+2) = M(2)*MC(2)*QMIXSS(SN(2),2,J)
+ & +SLFCH(SN(2),NSP)*QMIXSS(SN(2),1,J)
+ MX2(2+J) = QMIXSS(SN(2),1,J)
+ A(J+4) = M(3)*MC(1)*QMIXSS(SN(3),2,J)
+ & +SLFCH(SN(3),NSP)*QMIXSS(SN(3),1,J)
+ B(J+4) = MSGN*(M(3)*MC(1)*QMIXSS(SN(3),1,J)
+ & +SRFCH(SN(3),NSP)*QMIXSS(SN(3),2,J))
+ MX2(J+4) = QMIXSS(SN(3),2,J)
+ ENDDO
+ ENDIF
+ SN(1) = SN(1) + 424
+ SB(1) = SB(1) + 436
+ DO J=2,3
+ SN(J) = SN(J) + 400
+ SB(J) = SB(J) + 412
+ ENDDO
+ ENDIF
+ DO K=1,3
+ SM(2*K-1) = RMASS(SN(K))
+ SM(2*K) = RMASS(SB(K))
+ SW(2*K-1) = HBAR/RLTIM(SN(K))
+ SW(2*K) = HBAR/RLTIM(SB(K))
+ ENDDO
+ ND = 3
+ DO K=1,3
+ LAMD(K) = ONE
+ ENDDO
+ INFCOL = ONE
+ ELSEIF(IG.EQ.449) THEN
+C--GLUINO
+C--First obtian the masses and widths needed
+ AM = RMASS(IG)
+ ND = 3
+C--Calculate the combinations of couplings needed
+ IF(ID(1).LE.12.AND.ID(2).LE.12.AND.ID(3).LE.12) THEN
+C--first for the UDD modes
+ INFCOL = -0.5D0
+C--Couplings
+ DO I=1,3
+ DO J=1,2
+ A(2*I-2+J) = -QMIXSS(SN(I),1,J)
+ B(2*I-2+J) = QMIXSS(SN(I),2,J)
+ MX2(2*I-2+J) = QMIXSS(SN(I),2,J)
+ ENDDO
+ SN(I) = SN(I)+400
+ SB(I) = SB(I)+412
+ ENDDO
+ ELSE
+ INFCOL = ONE
+C--Now for both types of LQD modes
+ IF(MOD(SN(1),2).EQ.0) THEN
+C--First the neutrino,down,antidown mode
+ DO J=1,2
+ A(J) = ZERO
+ B(J) = ZERO
+ MX2(J) = ZERO
+ A(J+2) = QMIXSS(SN(2),2,J)
+ B(J+2) = -QMIXSS(SN(2),1,J)
+ MX2(J+2) = QMIXSS(SN(2),1,J)
+ A(J+4) = -QMIXSS(SN(3),1,J)
+ B(J+4) = QMIXSS(SN(3),2,J)
+ MX2(4+J) = QMIXSS(SN(3),2,J)
+ ENDDO
+ ELSEIF(MOD(SN(1),2).EQ.1) THEN
+C--Now the charged lepton, antiup,down modes
+ DO J=1,2
+ A(J) = ZERO
+ B(J) = ZERO
+ MX2(J) = ZERO
+ A(J+2) = QMIXSS(SN(2),2,J)
+ B(J+2) = -QMIXSS(SN(2),1,J)
+ MX2(J+2) = QMIXSS(SN(2),1,J)
+ A(J+4) = -QMIXSS(SN(3),1,J)
+ B(J+4) = QMIXSS(SN(3),2,J)
+ MX2(J+4) = QMIXSS(SN(3),2,J)
+ ENDDO
+ ENDIF
+ SN(1) = SN(1) + 424
+ SB(1) = SB(1) + 436
+ DO K=2,3
+ SN(K) = SN(K) + 400
+ SB(K) = SB(K) + 412
+ ENDDO
+ ENDIF
+ DO K=1,3
+ SM(2*K-1) = RMASS(SN(K))
+ SM(2*K) = RMASS(SB(K))
+ SW(2*K-1) = HBAR/RLTIM(SN(K))
+ SW(2*K) = HBAR/RLTIM(SB(K))
+ ENDDO
+ DO K=1,3
+ LAMD(K) = ONE
+ ENDDO
+ ELSEIF(IG.GE.454.AND.IG.LE.457) THEN
+C--CHARGINO
+ CSP = IG-453
+ IF(CSP.GT.2) CSP = CSP-2
+ AM = RMASS(IG)
+ INFCOL = -ONE
+ MSGN = WSGNSS(CSP)
+ MC(1) = ONE/(SQRT(2.0D0)*MW*COSB)
+ MC(2) = ONE/(SQRT(2.0D0)*MW*SINB)
+C--Calculate the combinations of the couplings needed
+ IF(ID(1).GT.120.AND.ID(2).GT.120.AND.ID(3).GT.120) THEN
+C--first for the LLE modes, three modes
+ IF(MOD(SN(1),2).EQ.0.AND.MOD(SN(3),2).EQ.0) THEN
+C--the one diagram mode nubar,positron, nu
+ DO J=1,2
+ A(J+4) = LMIXSS(SN(3)-1,1,J)*WMXUSS(CSP,1)
+ & -RMASS(SN(3)+119)*MC(1)*LMIXSS(SN(3)-1,2,J)*WMXUSS(CSP,2)
+ B(J+4) = ZERO
+ MX2(J+4) = LMIXSS(SN(3)-1,2,J)
+ ENDDO
+ ND = 1
+ SN(3) = SN(3)+423
+ SB(3) = SB(3)+435
+ ELSEIF(MOD(SN(1),2).EQ.0.AND.MOD(SN(2),2).EQ.0) THEN
+C--the first two diagram mode nu, nu, positron
+ DO J=1,2
+ A(J) = ZERO
+ B(J) = LMIXSS(SN(1)-1,1,J)*WMXUSS(CSP,1)
+ & -RMASS(SN(1)+119)*MC(1)*LMIXSS(SN(1)-1,2,J)*WMXUSS(CSP,2)
+ A(J+2) = ZERO
+ B(J+2) = LMIXSS(SN(2)-1,1,J)*WMXUSS(CSP,1)
+ & -RMASS(SN(2)+119)*MC(1)*LMIXSS(SN(2)-1,2,J)*WMXUSS(CSP,2)
+ MX2(J) = LMIXSS(SN(1)-1,1,J)
+ MX2(J+2) = LMIXSS(SN(2)-1,1,J)
+ ENDDO
+ ND = 2
+ DO J=1,2
+ SN(J) = SN(J)+423
+ SB(J) = SB(J)+435
+ ENDDO
+ ELSE
+C--the second two diagram mode positron, positron, electron
+ DO J=1,2
+ A(J) = -M(1)*WMXUSS(CSP,2)*MC(1)*LMIXSS(SN(1)+1,1,J)
+ B(J) = MSGN*WMXVSS(CSP,1)*LMIXSS(SN(1)+1,1,J)
+ A(J+2) = -M(2)*WMXUSS(CSP,2)*MC(1)*LMIXSS(SN(2)+1,1,J)
+ B(J+2) = MSGN*WMXVSS(CSP,1)*LMIXSS(SN(2)+1,1,J)
+ MX2(J) = LMIXSS(SN(1)+1,1,J)
+ MX2(J+2) = LMIXSS(SN(2)+1,1,J)
+ ENDDO
+ DO J=1,2
+ SN(J) = SN(J)+425
+ SB(J) = SB(J)+437
+ ENDDO
+ ND = 2
+ ENDIF
+ DO K=1,3
+ LAMD(K) = ONE
+ ENDDO
+ ELSEIF(ID(1).LE.12.AND.ID(2).LE.12.AND.ID(3).LE.12) THEN
+C--now for the UDD
+ IF(MOD(SN(1),2).EQ.0) THEN
+C--two diagram mode
+ LAMD(1) = LAMDA3(SN(2)/2,SN(1)/2,(SN(3)+1)/2)
+ LAMD(2) = LAMDA3(SN(1)/2,SN(2)/2,(SN(3)+1)/2)
+ DO J=1,2
+ A(J) = WMXUSS(CSP,1)*QMIXSS(SN(1)-1,1,J)
+ & -RMASS(SN(1)-1)*MC(1)*WMXUSS(CSP,2)*QMIXSS(SN(1)-1,2,J)
+ B(J) = -MSGN*M(2)*WMXVSS(CSP,2)*QMIXSS(SN(1)-1,1,J)
+ A(J+2) = WMXUSS(CSP,1)*QMIXSS(SN(2)-1,1,J)
+ & -RMASS(SN(2)-1)*MC(1)*WMXUSS(CSP,2)*QMIXSS(SN(2)-1,2,J)
+ B(J+2) = -MSGN*M(2)*WMXVSS(CSP,2)*QMIXSS(SN(2)-1,1,J)
+ MX2(J) = QMIXSS(SN(1)-1,2,J)
+ MX2(J+2) = QMIXSS(SN(2)-1,2,J)
+ ENDDO
+ DO J=1,2
+ SN(J) = SN(J) + 399
+ SB(J) = SB(J) + 411
+ ENDDO
+ ND = 2
+ ELSE
+C--three diagram mode
+ LAMD(1) = LAMDA3((SN(1)+1)/2,(SN(2)+1)/2,(SN(3)+1)/2)
+ LAMD(2) = LAMDA3((SN(2)+1)/2,(SN(1)+1)/2,(SN(3)+1)/2)
+ LAMD(3) = LAMDA3((SN(3)+1)/2,(SN(2)+1)/2,(SN(1)+1)/2)
+ DO I=1,3
+ DO J=1,2
+ A(J+2*I-2) = MSGN*(WMXVSS(CSP,1)*QMIXSS(SN(I)+1,1,J)
+ & -RMASS(SN(I)+1)*MC(2)*WMXVSS(CSP,2)*QMIXSS(SN(I)+1,2,J))
+ B(J+2*I-2) = -M(I)*MC(1)*WMXUSS(CSP,2)
+ & *QMIXSS(SN(I)+1,1,J)
+ MX2(J+2*I-2) = QMIXSS(SN(I)+1,2,J)
+ ENDDO
+ SN(I) = SN(I) + 401
+ SB(I) = SB(I) + 413
+ ENDDO
+ ND = 3
+ ENDIF
+ ELSE
+C--now for the LQD modes
+ IF(MOD(SN(2),2).EQ.1.AND.MOD(SN(3),2).EQ.0) THEN
+C--first one diagram mode nubar, dbar, up
+ DO J=1,2
+ A(J+4) = -MSGN*M(3)*WMXVSS(CSP,2)*MC(2)*
+ & QMIXSS(SN(3)-1,1,J)
+ B(J+4) = WMXUSS(CSP,1)*QMIXSS(SN(3)-1,1,J)
+ & -RMASS(SN(3)-1)*MC(1)*WMXUSS(CSP,2)*QMIXSS(SN(3)-1,2,1)
+ MX2(J+4) = QMIXSS(SN(3)-1,2,J)
+ ENDDO
+ SN(3) = SN(3) + 399
+ SB(3) = SB(3) + 411
+ ND = 1
+ ELSEIF(MOD(SN(2),2).EQ.0.AND.MOD(SN(3),2).EQ.0) THEN
+C--second one diagram mode positron, ubar, up
+ DO J=1,2
+ A(J+4) = -MSGN*M(3)*WMXVSS(CSP,2)*MC(2)*
+ & QMIXSS(SN(3)-1,1,J)
+ B(J+4) = WMXUSS(CSP,1)*QMIXSS(SN(3)-1,1,J)
+ & -RMASS(SN(3)-1)*MC(1)*WMXUSS(CSP,2)*QMIXSS(SN(3)-1,2,1)
+ MX2(J+4) = QMIXSS(SN(3)-1,2,J)
+ ENDDO
+ SN(3) = SN(3) + 399
+ SB(3) = SB(3) + 411
+ ND = 1
+ ELSEIF(MOD(SN(2),2).EQ.1.AND.MOD(SN(3),2).EQ.1) THEN
+C--first two diagram mode positron, dbar, down
+ DO J=1,2
+ A(J) = -M(1)*MC(1)*WMXUSS(CSP,2)*LMIXSS(SN(1)+1,1,J)
+ B(J) = MSGN*WMXVSS(CSP,1)*LMIXSS(SN(2)+1,1,J)
+ A(J+2) = -M(2)*WMXUSS(CSP,2)*MC(1)*QMIXSS(SN(2)+1,1,J)
+ B(J+2) = MSGN*(WMXVSS(CSP,1)*QMIXSS(SN(2)+1,1,J)
+ & -RMASS(SN(2)+1)*MC(2)*WMXVSS(CSP,2)*QMIXSS(SN(2)+1,2,J))
+ MX2(J) = LMIXSS(SN(1)+1,1,J)
+ MX2(J+2) = QMIXSS(SN(2)+1,1,J)
+ ENDDO
+ SN(1) = SN(1) + 425
+ SB(1) = SB(1) + 437
+ SN(2) = SN(2) + 401
+ SB(2) = SB(2) + 413
+ ND = 2
+ ELSE
+C--second two diagram mode nu, up, dbar
+ DO J=1,2
+ A(J) = ZERO
+ B(J) = WMXUSS(CSP,1)*LMIXSS(SN(1)-1,1,J)
+ & -RMASS(119+SN(1))*MC(1)*WMXUSS(CSP,2)*LMIXSS(SN(1)-1,2,J)
+ A(J+2) = -MSGN*M(2)*MC(2)*WMXVSS(CSP,2)*
+ & QMIXSS(SN(2)-1,1,J)
+ B(J+2) = WMXUSS(CSP,1)*QMIXSS(SN(2)-1,1,J)
+ & -RMASS(SN(2)-1)*MC(1)*WMXUSS(CSP,2)*QMIXSS(SN(2)-1,2,J)
+ MX2(J) = LMIXSS(SN(1)-1,1,J)
+ MX2(J+2) = QMIXSS(SN(2)-1,1,J)
+ ENDDO
+ SN(1) = SN(1) + 423
+ SB(1) = SB(1) + 435
+ SN(2) = SN(2) + 399
+ SB(2) = SB(2) + 411
+ ND = 2
+ ENDIF
+ DO K=1,3
+ LAMD(K) = ONE
+ ENDDO
+ ENDIF
+ IF(ND.EQ.1) THEN
+ DO K=1,2
+ SM(2*K-1) = 0.0D0
+ SM(2*K) = 0.0D0
+ SW(2*K-1) = 0.0D0
+ SW(2*K) = 0.0D0
+ ENDDO
+ SM(5) = RMASS(SN(3))
+ SM(6) = RMASS(SB(3))
+ SW(5) = HBAR/RLTIM(SN(3))
+ SW(6) = HBAR/RLTIM(SB(3))
+ ELSE
+ DO K=1,2
+ SM(2*K-1) = RMASS(SN(K))
+ SM(2*K) = RMASS(SB(K))
+ SW(2*K-1) = HBAR/RLTIM(SN(K))
+ SW(2*K) = HBAR/RLTIM(SB(K))
+ SM(4+K) = ZERO
+ SW(4+K) = ZERO
+ ENDDO
+ ENDIF
+ ELSE
+C--UNKNOWN
+ CALL HWWARN('HWDRME',500,*999)
+ ENDIF
+C--Set mixing to zero if diagram not available
+ IF((AM.LT.(ABS(SM(1))+M(1)).OR.ABS(SM(1)).LT.(M(2)+M(3)))
+ & .AND.ABS(MX2(1)).GT.ZERO.AND.ND.NE.1) MX(1) = MX2(1)*LAMD(1)
+ IF((AM.LT.(ABS(SM(2))+M(1)).OR.ABS(SM(2)).LT.(M(2)+M(3)))
+ & .AND.ABS(MX2(2)).GT.ZERO.AND.ND.NE.1) MX(2) = MX2(2)*LAMD(1)
+ IF((AM.LT.(ABS(SM(3))+M(2)).OR.ABS(SM(3)).LT.(M(1)+M(3)))
+ & .AND.ABS(MX2(3)).GT.ZERO.AND.ND.NE.1) MX(3) = MX2(3)*LAMD(2)
+ IF((AM.LT.(ABS(SM(4))+M(2)).OR.ABS(SM(4)).LT.(M(1)+M(3)))
+ & .AND.ABS(MX2(4)).GT.ZERO.AND.ND.NE.1) MX(4) = MX2(4)*LAMD(2)
+ IF((AM.LT.(ABS(SM(5))+M(3)).OR.ABS(SM(5)).LT.(M(1)+M(2)))
+ & .AND.ABS(MX2(5)).GT.ZERO.AND.ND.NE.2) MX(5) = MX2(5)*LAMD(3)
+ IF((AM.LT.(ABS(SM(6))+M(3)).OR.ABS(SM(6)).LT.(M(1)+M(2)))
+ & .AND.ABS(MX2(6)).GT.ZERO.AND.ND.NE.2) MX(6) = MX2(6)*LAMD(3)
+C--Calculate the limiting points
+ DO J=1,2
+ IF(ND.NE.1) THEN
+ IF(ABS(MX(J)).GT.EPS) CALL HWDRM5(M23SQT(J),M13SQT(J),
+ & M12SQT(J),A(J),B(J),M(2),M(3),M(1),M(4),SM(J),SW(J))
+ IF(ABS(MX(J+2)).GT.EPS) CALL HWDRM5(M13SQT(2+J),M23SQT(2+J),
+ & M12SQT(2+J),A(2+J),B(2+J),M(1),M(3),M(2),M(4),SM(2+J),SW(2+J))
+ ENDIF
+ IF(ND.NE.2) THEN
+ IF(ABS(MX(J+4)).GT.EPS) CALL HWDRM5(M12SQT(4+J),M23SQT(4+J),
+ & M13SQT(4+J),A(4+J),B(4+J),M(1),M(2),M(3),M(4),SM(4+J),SW(4+J))
+ ENDIF
+ ENDDO
+C--Now evaluate the limit using these points
+ LIMIT = ZERO
+ DO 100 I=1,6
+ IF(ABS(MX(I)).LT.EPS) GOTO 100
+ LIMIT = LIMIT+HWDRM1(TEST,M12SQT(I),M13SQT(I),M23SQT(I),A,B,MX,
+ & M,SM,SW,INFCOL,AM,0,ND)
+ 100 CONTINUE
+ LIMIT = TWO*LIMIT
+C--Now evaluate at a random point
+ MTRY = 0
+ 25 MTRY = MTRY+1
+ LTRY = 0
+ 35 LTRY = LTRY+1
+ CALL HWDTHR(PHEP(1,LHEP),PHEP(1,MHEP),
+ & PHEP(1,MHEP+1),PHEP(1,MHEP+2),HWDPWT)
+C--Now calculate the m12sq etc for the actual point
+ M12SQ = M(1)**2+M(2)**2+2*HWULDO(PHEP(1,MHEP),PHEP(1,MHEP+1))
+ M13SQ = M(1)**2+M(3)**2+2*HWULDO(PHEP(1,MHEP),PHEP(1,MHEP+2))
+ M23SQ = M(2)**2+M(3)**2+2*HWULDO(PHEP(1,MHEP+1),PHEP(1,MHEP+2))
+C--Now calulate the matrix element
+ TEST(4) = HWDRM1(TEST,M12SQ,M13SQ,M23SQ,A,B,MX,
+ & M,SM,SW,INFCOL,AM,1,ND)
+C--Now test the value againest the limit
+ RAND = HWR()*LIMIT
+ IF(TEST(4).GT.LIMIT) THEN
+ LIMIT = 1.1D0*TEST(4)
+ CALL HWWARN('HWDRME',51,*150)
+ ENDIF
+ 150 IF(TEST(4).LT.RAND.AND.LTRY.LT.NETRY) THEN
+ GOTO 35
+ ELSEIF(LTRY.GE.NETRY) THEN
+ IF(MTRY.LE.NETRY) THEN
+ LIMIT = LIMIT*0.9D0
+ CALL HWWARN('HWDRME',52,*25)
+ ELSE
+ CALL HWWARN('HWDRME',100,*999)
+ ENDIF
+ ENDIF
+C--Reorder the particles in gluino decay to get angular ordering right
+ IF(IG.EQ.449.AND.ID(1).LE.12.AND.ID(2).LE.12.AND.ID(3).LE.12) THEN
+ DO LTRY=1,3
+ IF(TEST(LTRY).GT.RAND) THEN
+ IF(LTRY.EQ.2) THEN
+ IDHWTP = IDHW(MHEP)
+ IDHW(MHEP) = IDHW(MHEP+1)
+ IDHW(MHEP+1) = IDHWTP
+ IDHPTP = IDHEP(MHEP)
+ IDHEP(MHEP) = IDHEP(MHEP+1)
+ IDHEP(MHEP+1) = IDHPTP
+ CALL HWVEQU(5,PHEP(1,MHEP),DECMOM)
+ CALL HWVEQU(5,PHEP(1,MHEP+1),PHEP(1,MHEP))
+ CALL HWVEQU(5,DECMOM,PHEP(1,MHEP+1))
+ ELSEIF(LTRY.EQ.3) THEN
+ IDHWTP = IDHW(MHEP)
+ IDHW(MHEP) = IDHW(MHEP+2)
+ IDHW(MHEP+2) = IDHWTP
+ IDHPTP = IDHEP(MHEP)
+ IDHEP(MHEP) = IDHEP(MHEP+2)
+ IDHEP(MHEP+2) = IDHPTP
+ DO I=1,5
+ CALL HWVEQU(5,PHEP(1,MHEP),DECMOM)
+ CALL HWVEQU(5,PHEP(1,MHEP+2),PHEP(1,MHEP))
+ CALL HWVEQU(5,DECMOM,PHEP(1,MHEP+2))
+ ENDDO
+ ENDIF
+ GOTO 52
+ ENDIF
+ RAND=RAND-TEST(LTRY)
+ ENDDO
+ ENDIF
+ 52 CONTINUE
+ 999 END
+CDECK ID>, HWDRM1.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ FUNCTION HWDRM1(TEST,M12SQ,M13SQ,M23SQ,A,B,MX,M,SM,SW
+ & ,INFCOL,AM,LM,ND)
+C-----------------------------------------------------------------------
+C FUNCTION TO GIVE THE R-PARITY VIOLATING MATRIX ELEMENT AT A GIVEN
+C PHASE-SPACE POINT
+C-----------------------------------------------------------------------
+ IMPLICIT NONE
+ DOUBLE PRECISION M12SQ,M13SQ,M23SQ,MX(6),A(6),B(6),SM(6),SW(6),
+ & INFCOL,AM,TERM(21),TEST(4),PLN,NPLN,ZERO,
+ & M(4),HWDRM1,HWDRM2,HWDRM3,HWDRM4
+ PARAMETER (ZERO=0)
+ EXTERNAL HWDRM2,HWDRM3,HWDRM4
+ INTEGER LM,K,ND
+C--Zero the array
+ DO K=1,21
+ TERM(K) = 0.0D0
+ ENDDO
+ HWDRM1 = 0.0D0
+C--The amplitude
+ IF(ABS(MX(1)).GT.ZERO.AND.ND.NE.1) THEN
+ TERM(1) = MX(1)**2*HWDRM2(M23SQ,M(2),M(3),M(1),M(4),SM(1),
+ & SW(1),A(1),B(1))
+ IF(ABS(MX(2)).GT.ZERO) TERM(7)= MX(1)*MX(2)*HWDRM3(M23SQ,M(2),
+ & M(3),M(1),M(4),SM(1),SM(2),SW(1),SW(2),A(1),A(2),B(1),B(2))
+ IF(ABS(MX(3)).GT.ZERO) TERM(10)=-MX(1)*MX(3)*HWDRM4(M13SQ,M23SQ,
+ & M(1),M(3),M(2),M(4),SM(3),SM(1),SW(3),SW(1),A(1),A(3),B(1),B(3))
+ IF(ABS(MX(4)).GT.ZERO) TERM(11)=-MX(1)*MX(4)*HWDRM4(M13SQ,M23SQ,
+ & M(1),M(3),M(2),M(4),SM(4),SM(1),SW(4),SW(1),A(1),A(4),B(1),B(4))
+ IF(ABS(MX(5)).GT.ZERO) TERM(12)=-MX(1)*MX(5)*HWDRM4(M23SQ,M12SQ,
+ & M(3),M(2),M(1),M(4),SM(1),SM(5),SW(1),SW(5),A(5),A(1),B(5),B(1))
+ IF(ABS(MX(6)).GT.ZERO) TERM(13)=-MX(1)*MX(6)*HWDRM4(M23SQ,M12SQ,
+ & M(3),M(2),M(1),M(4),SM(1),SM(6),SW(1),SW(6),A(6),A(1),B(6),B(1))
+ ENDIF
+ IF(ABS(MX(2)).GT.ZERO.AND.ND.NE.1) THEN
+ TERM(2) = MX(2)**2*HWDRM2(M23SQ,M(2),M(3),M(1),M(4),SM(2),
+ & SW(2),A(2),B(2))
+ IF(ABS(MX(3)).GT.ZERO) TERM(14)=-MX(2)*MX(3)*HWDRM4(M13SQ,M23SQ,
+ & M(1),M(3),M(2),M(4),SM(3),SM(2),SW(3),SW(2),A(2),A(3),B(2),B(3))
+ IF(ABS(MX(4)).GT.ZERO) TERM(15)=-MX(2)*MX(4)*HWDRM4(M13SQ,M23SQ,
+ & M(1),M(3),M(2),M(4),SM(4),SM(2),SW(4),SW(2),A(2),A(4),B(2),B(4))
+ IF(ABS(MX(5)).GT.ZERO) TERM(16)=-MX(2)*MX(5)*HWDRM4(M23SQ,M12SQ,
+ & M(3),M(2),M(1),M(4),SM(2),SM(5),SW(2),SW(5),A(5),A(2),B(5),B(2))
+ IF(ABS(MX(6)).GT.ZERO) TERM(17)=-MX(2)*MX(6)*HWDRM4(M23SQ,M12SQ,
+ & M(3),M(2),M(1),M(4),SM(2),SM(6),SW(2),SW(6),A(6),A(2),B(6),B(2))
+ ENDIF
+ IF(ABS(MX(3)).GT.ZERO.AND.ND.NE.1) THEN
+ TERM(3) = MX(3)**2*HWDRM2(M13SQ,M(1),M(3),M(2),M(4),SM(3),
+ & SW(3),A(3),B(3))
+ IF(ABS(MX(4)).GT.ZERO) TERM(8)= MX(3)*MX(4)*HWDRM3(M13SQ,M(1),
+ & M(3),M(2),M(4),SM(3),SM(4),SW(3),SW(4),A(3),A(4),B(3),B(4))
+ IF(ABS(MX(5)).GT.ZERO) TERM(18)=-MX(3)*MX(5)*HWDRM4(M12SQ,M13SQ,
+ & M(2),M(1),M(3),M(4),SM(5),SM(3),SW(5),SW(3),A(3),A(5),B(3),B(5))
+ IF(ABS(MX(6)).GT.ZERO) TERM(19)=-MX(3)*MX(6)*HWDRM4(M12SQ,M13SQ,
+ & M(2),M(1),M(3),M(4),SM(6),SM(3),SW(6),SW(3),A(3),A(6),B(3),B(6))
+ ENDIF
+ IF(ABS(MX(4)).GT.ZERO.AND.ND.NE.1) THEN
+ TERM(4) = MX(4)**2*HWDRM2(M13SQ,M(1),M(3),M(2),M(4),SM(4),
+ & SW(4),A(4),B(4))
+ IF(ABS(MX(5)).GT.ZERO) TERM(20)=-MX(4)*MX(5)*HWDRM4(M12SQ,M13SQ,
+ & M(2),M(1),M(3),M(4),SM(5),SM(4),SW(5),SW(4),A(4),A(5),B(4),B(5))
+ IF(ABS(MX(6)).GT.ZERO) TERM(21)=-MX(4)*MX(6)*HWDRM4(M12SQ,M13SQ,
+ & M(2),M(1),M(3),M(4),SM(6),SM(4),SW(6),SW(4),A(4),A(6),B(4),B(6))
+ ENDIF
+ IF(ABS(MX(5)).GT.ZERO.AND.ND.NE.2) THEN
+ TERM(5) = MX(5)**2*HWDRM2(M12SQ,M(1),M(2),M(3),M(4),SM(5),
+ & SW(5),A(5),B(5))
+ IF(ABS(MX(6)).GT.ZERO) TERM(9)= MX(5)*MX(6)*HWDRM3(M12SQ,M(1),
+ & M(2),M(3),M(4),SM(5),SM(6),SW(5),SW(6),A(5),A(6),B(5),B(6))
+ ENDIF
+ IF(ABS(MX(6)).GT.ZERO.AND.ND.NE.2) TERM(6) = MX(6)**2*
+ & HWDRM2(M12SQ,M(1),M(2),M(3),M(4),SM(6),SW(6),A(6),B(6))
+ DO K=10,21
+ TERM(K)=TERM(K)*INFCOL
+ ENDDO
+C--Add them up
+ DO K=1,21
+ HWDRM1 = HWDRM1+TERM(K)
+ ENDDO
+C--Different colour flows for the gluino
+ IF(LM.NE.0) THEN
+ NPLN = 0.0D0
+ PLN = 0.0D0
+ DO K=1,9
+ PLN = PLN+TERM(K)
+ ENDDO
+ DO K=10,21
+ NPLN= NPLN+TERM(K)
+ ENDDO
+ DO K=1,3
+ TEST(K) = (TERM(2*K-1)+TERM(2*K)+TERM(6+K))*(1+NPLN/PLN)
+ ENDDO
+ ELSE
+ DO K=1,3
+ TEST(K) = 0.0D0
+ ENDDO
+ ENDIF
+ IF(TEST(4).LT.ZERO) CALL HWWARN('HWDRM1',50,*999)
+ 999 END
+CDECK ID>, HWDRM2.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ FUNCTION HWDRM2(X,MA,MB,MC,MD,MR1,GAM1,A,B)
+C-----------------------------------------------------------------------
+C Function to compute the matrix element squared part of a 3-body
+C R-parity decay
+C-----------------------------------------------------------------------
+ IMPLICIT NONE
+ DOUBLE PRECISION X,MA,MB,MC,MD,A,B,HWDRM2,MR1,GAM1
+ HWDRM2 = (X - MA**2 - MB**2)*(4*A*B*MC*MD +
+ & (A**2 + B**2)*(-X + MC**2 + MD**2))/
+ & ((X-MR1**2)**2+GAM1**2*MR1**2)
+ END
+CDECK ID>, HWDRM3.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ FUNCTION HWDRM3(X,MA,MB,MC,MD,MR1,MR2,GAM1,GAM2,A1,A2,B1,B2)
+C-----------------------------------------------------------------------
+C Function to compute the light/heavy interference part of a 3-body
+C R-parity decay
+C-----------------------------------------------------------------------
+ IMPLICIT NONE
+ DOUBLE PRECISION X,MA,MB,MC,MD,A1,A2,B1,B2,HWDRM3,MR1,MR2,GAM1
+ & ,GAM2
+C
+ HWDRM3 = 2*(X - MA**2 - MB**2)*(2*(A2*B1 + A1*B2)*MC*MD +
+ & (A1*A2 + B1*B2)*(-X + MC**2 + MD**2))*
+ & (GAM1*GAM2*MR1*MR2 + (X - MR1**2)*(X - MR2**2))/
+ & (((X-MR1**2)**2+GAM1**2*MR1**2)*((X-MR2**2)**2+GAM2**2*MR2**2))
+ END
+CDECK ID>, HWDRM4.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ FUNCTION HWDRM4(X,Y,MA,MB,MC,MD,MR1,MR2,GAM1,GAM2,A1,A2,B1,B2)
+C-----------------------------------------------------------------------
+C Function to compute the interference part of a 3-body
+C R-parity decay
+C-----------------------------------------------------------------------
+ IMPLICIT NONE
+ DOUBLE PRECISION X,Y,MA,MB,MC,MD,A1,A2,B1,B2,HWDRM4,MR1,MR2,GAM1
+ & ,GAM2
+C
+ HWDRM4 = 2*((GAM1*GAM2*MR1*MR2 + (X - MR1**2)*(Y - MR2**2))*
+ & (A2*B1*MC*MD*(X - MA**2 - MB**2) +
+ & A1*A2*MA*MC*(X + Y - MA**2 - MC**2) +
+ & A1*B2*MA*MD*(Y - MB**2 - MC**2) +
+ & B1*B2*(X*Y - MA**2*MC**2 - MB**2*MD**2)))/
+ & (((X-MR1**2)**2+GAM1**2*MR1**2)*((Y-MR2**2)**2+GAM2**2*MR2**2))
+ END
+CDECK ID>, HWDRM5.
+*CMZ :- -20/07/99 10:56:12 by Peter Richardson
+*-- Author : Peter Richardson
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDRM5(X,Y,Z,A,B,MA,MB,MC,MD,MR,GAM)
+C-----------------------------------------------------------------------
+C Subroutine to find the maximum of the ME
+C-----------------------------------------------------------------------
+ IMPLICIT NONE
+ DOUBLE PRECISION X,Y,Z,MA,MB,MC,MD,MR,GAM,RES(3),A,B,C,D,
+ & E2S,E3S,E2M,E3M,LOW,UPP,HWRUNI,EPS,ZERO
+ EXTERNAL HWRUNI
+ PARAMETER(EPS=1D-9,ZERO=0)
+ C = A**2+B**2
+ D = 4*A*B
+ RES(1) = -D*(MA**2 + MB**2)*MC*MD +
+ & C*(GAM**2*MR**2 + MR**4 - MA**2*MC**2 - MB**2*MC**2 -
+ & MA**2*MD**2 - MB**2*MD**2)
+ RES(2) = (GAM**2*MR**2 + (-MR**2 + MA**2 + MB**2)**2)*
+ & (D**2*MC**2*MD**2 +
+ & 2*C*D*MC*MD*(-MR**2 + MC**2 + MD**2) +
+ & C**2*(GAM**2*MR**2 + (-MR**2 + MC**2 + MD**2)**2))
+ RES(3) = -D*MC*MD+C*(2*MR**2-(MA**2+MB**2+MC**2+MD**2))
+ IF(RES(2).GT.ZERO) THEN
+ RES(2) = SQRT(RES(2))
+ ELSE
+ RES(2) = 0.0D0
+ ENDIF
+ IF((RES(1)+RES(2))/RES(3).GT.(MD-MC)**2.OR.
+ & (RES(1)+RES(2))/RES(3).LT.(MA+MB)**2) THEN
+ X = (RES(1)-RES(2))/RES(3)
+ ELSE
+ X = (RES(1)+RES(2))/RES(3)
+ ENDIF
+ IF(X.GT.(MD-MC)**2) X = (MD-MC)**2
+ IF(X.LT.(MA+MB)**2) X = (MA+MB)**2
+ E2S = (X-MA**2+MB**2)/(2*SQRT(X))
+ E3S = (MD**2-X-MC**2)/(2*SQRT(X))
+ E2M = E2S**2-MB**2
+ E3M = E3S**2-MC**2
+ IF(E2M.LT.ZERO) THEN
+ IF(ABS(E2M/E2S).GT.EPS) CALL HWWARN('HWDRM5',2,*10)
+ 10 E2M= 0.0D0
+ ENDIF
+ IF(E3M.LT.ZERO) THEN
+ IF(ABS(E3M/E3S).GT.EPS) CALL HWWARN('HWDRM5',3,*20)
+ 20 E3M= 0.0D0
+ ENDIF
+ E2M = SQRT(E2M)
+ E3M = SQRT(E3M)
+ LOW = (E2S+E3S)**2-(E2M+E3M)**2
+ UPP = (E2S+E3S)**2-(E2M-E3M)**2
+ Y = HWRUNI(1,LOW,UPP)
+ Z = MA**2+MB**2+MC**2+MD**2-X-Y
+ END
+CDECK ID>, HWDPWT.
+*CMZ :- -26/04/91 11.11.55 by Bryan Webber
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ FUNCTION HWDPWT(EMSQ,A,B,C)
+C-----------------------------------------------------------------------
+C MATRIX ELEMENT SQUARED FOR PHASE SPACE DECAY
+C-----------------------------------------------------------------------
+ DOUBLE PRECISION HWDPWT,EMSQ,A,B,C
+ HWDPWT=1.
+ END
+CDECK ID>, HWDTHR.
+*CMZ :- -26/04/91 14.55.44 by Federico Carminati
+*-- Author : Bryan Webber
+C-----------------------------------------------------------------------
+ SUBROUTINE HWDTHR(P0,P1,P2,P3,WEIGHT)
+C-----------------------------------------------------------------------
+C GENERATES THREE-BODY DECAY 0->1+2+3 DISTRIBUTED
+C ACCORDING TO PHASE SPACE * WEIGHT
+C-----------------------------------------------------------------------
+ DOUBLE PRECISION HWR,HWRUNI,A,B,C,D,AA,BB,CC,DD,EE,FF,PP,QQ,WW,
+ & RR,PCM1,PC23,WEIGHT,P0(5),P1(5),P2(5),P3(5),P23(5),TWO
+ EXTERNAL HWR,HWRUNI,WEIGHT
+ PARAMETER (TWO=2.D0)
+ A=P0(5)+P1(5)
+ B=P0(5)-P1(5)
+ C=P2(5)+P3(5)
+ IF (B.LT.C) CALL HWWARN('HWDTHR',100,*999)
+ D=ABS(P2(5)-P3(5))
+ AA=A*A
+ BB=B*B
+ CC=C*C
+ DD=D*D
+ EE=(B-C)*(A-D)
+ A=0.5*(AA+BB)
+ B=0.5*(CC+DD)
+ C=4./(A-B)**2
+C
+C CHOOSE MASS OF SUBSYSTEM 23 WITH PRESCRIBED DISTRIBUTION
+C
+ 10 FF=HWRUNI(0,BB,CC)
+ PP=(AA-FF)*(BB-FF)
+ QQ=(CC-FF)*(DD-FF)
+ WW=WEIGHT(FF,A,B,C)**2
+ RR=EE*FF*HWR()
+ IF (PP*QQ*WW.LT.RR*RR) GOTO 10
+C
+C FF IS MASS SQUARED OF SUBSYSTEM 23.
+C
+C DO 2-BODY DECAYS 0->1+23, 23->2+3
+C
+ P23(5)=SQRT(FF)
+ &nbs
git://git.uio.no / u/mrichter/AliRoot.git / commitdiff