* $Id$ C*********************************************************************** SUBROUTINE PYKLIM_HIJING(ILIM) C...Checks generated variables against pre-set kinematical limits; C...also calculates limits on variables used in generation. #include "ludat1_hijing.inc" #include "ludat2_hijing.inc" #include "ludat3_hijing.inc" #include "pypars_hijing.inc" #include "pysubs_hijing.inc" #include "pyint1_hijing.inc" #include "pyint2_hijing.inc" C...Common kinematical expressions. ISUB=MINT(1) IF(ISUB.EQ.96) GOTO 110 SQM3=VINT(63) SQM4=VINT(64) IF(ILIM.NE.1) THEN TAU=VINT(21) RM3=SQM3/(TAU*VINT(2)) RM4=SQM4/(TAU*VINT(2)) BE34=SQRT((1.-RM3-RM4)**2-4.*RM3*RM4) ENDIF PTHMIN=CKIN(3) IF(MIN(SQM3,SQM4).LT.CKIN(6)**2) PTHMIN=MAX(CKIN(3),CKIN(5)) IF(ILIM.EQ.0) THEN C...Check generated values of tau, y*, cos(theta-hat), and tau' against C...pre-set kinematical limits. YST=VINT(22) CTH=VINT(23) TAUP=VINT(26) IF(ISET(ISUB).LE.2) THEN X1=SQRT(TAU)*EXP(YST) X2=SQRT(TAU)*EXP(-YST) ELSE X1=SQRT(TAUP)*EXP(YST) X2=SQRT(TAUP)*EXP(-YST) ENDIF XF=X1-X2 IF(TAU*VINT(2).LT.CKIN(1)**2) MINT(51)=1 IF(CKIN(2).GE.0..AND.TAU*VINT(2).GT.CKIN(2)**2) MINT(51)=1 IF(X1.LT.CKIN(21).OR.X1.GT.CKIN(22)) MINT(51)=1 IF(X2.LT.CKIN(23).OR.X2.GT.CKIN(24)) MINT(51)=1 IF(XF.LT.CKIN(25).OR.XF.GT.CKIN(26)) MINT(51)=1 IF(YST.LT.CKIN(7).OR.YST.GT.CKIN(8)) MINT(51)=1 IF(ISET(ISUB).EQ.2.OR.ISET(ISUB).EQ.4) THEN PTH=0.5*BE34*SQRT(TAU*VINT(2)*(1.-CTH**2)) Y3=YST+0.5*LOG((1.+RM3-RM4+BE34*CTH)/(1.+RM3-RM4-BE34*CTH)) Y4=YST+0.5*LOG((1.+RM4-RM3-BE34*CTH)/(1.+RM4-RM3+BE34*CTH)) YLARGE=MAX(Y3,Y4) YSMALL=MIN(Y3,Y4) ETALAR=10. ETASMA=-10. STH=SQRT(1.-CTH**2) IF(STH.LT.1.E-6) GOTO 100 EXPET3=((1.+RM3-RM4)*SINH(YST)+BE34*COSH(YST)*CTH+ & SQRT(((1.+RM3-RM4)*COSH(YST)+BE34*SINH(YST)*CTH)**2-4.*RM3))/ & (BE34*STH) EXPET4=((1.-RM3+RM4)*SINH(YST)-BE34*COSH(YST)*CTH+ & SQRT(((1.-RM3+RM4)*COSH(YST)-BE34*SINH(YST)*CTH)**2-4.*RM4))/ & (BE34*STH) ETA3=LOG(MIN(1.E10,MAX(1.E-10,EXPET3))) ETA4=LOG(MIN(1.E10,MAX(1.E-10,EXPET4))) ETALAR=MAX(ETA3,ETA4) ETASMA=MIN(ETA3,ETA4) 100 CTS3=((1.+RM3-RM4)*SINH(YST)+BE34*COSH(YST)*CTH)/ & SQRT(((1.+RM3-RM4)*COSH(YST)+BE34*SINH(YST)*CTH)**2-4.*RM3) CTS4=((1.-RM3+RM4)*SINH(YST)-BE34*COSH(YST)*CTH)/ & SQRT(((1.-RM3+RM4)*COSH(YST)-BE34*SINH(YST)*CTH)**2-4.*RM4) CTSLAR=MAX(CTS3,CTS4) CTSSMA=MIN(CTS3,CTS4) IF(PTH.LT.PTHMIN) MINT(51)=1 IF(CKIN(4).GE.0..AND.PTH.GT.CKIN(4)) MINT(51)=1 IF(YLARGE.LT.CKIN(9).OR.YLARGE.GT.CKIN(10)) MINT(51)=1 IF(YSMALL.LT.CKIN(11).OR.YSMALL.GT.CKIN(12)) MINT(51)=1 IF(ETALAR.LT.CKIN(13).OR.ETALAR.GT.CKIN(14)) MINT(51)=1 IF(ETASMA.LT.CKIN(15).OR.ETASMA.GT.CKIN(16)) MINT(51)=1 IF(CTSLAR.LT.CKIN(17).OR.CTSLAR.GT.CKIN(18)) MINT(51)=1 IF(CTSSMA.LT.CKIN(19).OR.CTSSMA.GT.CKIN(20)) MINT(51)=1 IF(CTH.LT.CKIN(27).OR.CTH.GT.CKIN(28)) MINT(51)=1 ENDIF IF(ISET(ISUB).EQ.3.OR.ISET(ISUB).EQ.4) THEN IF(TAUP*VINT(2).LT.CKIN(31)**2) MINT(51)=1 IF(CKIN(32).GE.0..AND.TAUP*VINT(2).GT.CKIN(32)**2) MINT(51)=1 ENDIF ELSEIF(ILIM.EQ.1) THEN C...Calculate limits on tau C...0) due to definition TAUMN0=0. TAUMX0=1. C...1) due to limits on subsystem mass TAUMN1=CKIN(1)**2/VINT(2) TAUMX1=1. IF(CKIN(2).GE.0.) TAUMX1=CKIN(2)**2/VINT(2) C...2) due to limits on pT-hat (and non-overlapping rapidity intervals) TM3=SQRT(SQM3+PTHMIN**2) TM4=SQRT(SQM4+PTHMIN**2) YDCOSH=1. IF(CKIN(9).GT.CKIN(12)) YDCOSH=COSH(CKIN(9)-CKIN(12)) TAUMN2=(TM3**2+2.*TM3*TM4*YDCOSH+TM4**2)/VINT(2) TAUMX2=1. C...3) due to limits on pT-hat and cos(theta-hat) CTH2MN=MIN(CKIN(27)**2,CKIN(28)**2) CTH2MX=MAX(CKIN(27)**2,CKIN(28)**2) TAUMN3=0. IF(CKIN(27)*CKIN(28).GT.0.) TAUMN3= & (SQRT(SQM3+PTHMIN**2/(1.-CTH2MN))+ & SQRT(SQM4+PTHMIN**2/(1.-CTH2MN)))**2/VINT(2) TAUMX3=1. IF(CKIN(4).GE.0..AND.CTH2MX.LT.1.) TAUMX3= & (SQRT(SQM3+CKIN(4)**2/(1.-CTH2MX))+ & SQRT(SQM4+CKIN(4)**2/(1.-CTH2MX)))**2/VINT(2) C...4) due to limits on x1 and x2 TAUMN4=CKIN(21)*CKIN(23) TAUMX4=CKIN(22)*CKIN(24) C...5) due to limits on xF TAUMN5=0. TAUMX5=MAX(1.-CKIN(25),1.+CKIN(26)) VINT(11)=MAX(TAUMN0,TAUMN1,TAUMN2,TAUMN3,TAUMN4,TAUMN5) VINT(31)=MIN(TAUMX0,TAUMX1,TAUMX2,TAUMX3,TAUMX4,TAUMX5) IF(MINT(43).EQ.1.AND.(ISET(ISUB).EQ.1.OR.ISET(ISUB).EQ.2)) THEN VINT(11)=0.99999 VINT(31)=1.00001 ENDIF IF(VINT(31).LE.VINT(11)) MINT(51)=1 ELSEIF(ILIM.EQ.2) THEN C...Calculate limits on y* IF(ISET(ISUB).EQ.3.OR.ISET(ISUB).EQ.4) TAU=VINT(26) TAURT=SQRT(TAU) C...0) due to kinematics YSTMN0=LOG(TAURT) YSTMX0=-YSTMN0 C...1) due to explicit limits YSTMN1=CKIN(7) YSTMX1=CKIN(8) C...2) due to limits on x1 YSTMN2=LOG(MAX(TAU,CKIN(21))/TAURT) YSTMX2=LOG(MAX(TAU,CKIN(22))/TAURT) C...3) due to limits on x2 YSTMN3=-LOG(MAX(TAU,CKIN(24))/TAURT) YSTMX3=-LOG(MAX(TAU,CKIN(23))/TAURT) C...4) due to limits on xF YEPMN4=0.5*ABS(CKIN(25))/TAURT YSTMN4=SIGN(LOG(SQRT(1.+YEPMN4**2)+YEPMN4),CKIN(25)) YEPMX4=0.5*ABS(CKIN(26))/TAURT YSTMX4=SIGN(LOG(SQRT(1.+YEPMX4**2)+YEPMX4),CKIN(26)) C...5) due to simultaneous limits on y-large and y-small YEPSMN=(RM3-RM4)*SINH(CKIN(9)-CKIN(11)) YEPSMX=(RM3-RM4)*SINH(CKIN(10)-CKIN(12)) YDIFMN=ABS(LOG(SQRT(1.+YEPSMN**2)-YEPSMN)) YDIFMX=ABS(LOG(SQRT(1.+YEPSMX**2)-YEPSMX)) YSTMN5=0.5*(CKIN(9)+CKIN(11)-YDIFMN) YSTMX5=0.5*(CKIN(10)+CKIN(12)+YDIFMX) C...6) due to simultaneous limits on cos(theta-hat) and y-large or C... y-small CTHLIM=1.-4.*PTHMIN**2/(BE34*TAU*VINT(2)) if (CTHLIM .lt. 0) cthlim = 0. CTHLIM=SQRT(cthlim) RZMN=BE34*MAX(CKIN(27),-CTHLIM) RZMX=BE34*MIN(CKIN(28),CTHLIM) YEX3MX=(1.+RM3-RM4+RZMX)/MAX(1E-10,1.+RM3-RM4-RZMX) YEX4MX=(1.+RM4-RM3-RZMN)/MAX(1E-10,1.+RM4-RM3+RZMN) YEX3MN=MAX(1E-10,1.+RM3-RM4+RZMN)/(1.+RM3-RM4-RZMN) YEX4MN=MAX(1E-10,1.+RM4-RM3-RZMX)/(1.+RM4-RM3+RZMX) YSTMN6=CKIN(9)-0.5*LOG(MAX(YEX3MX,YEX4MX)) YSTMX6=CKIN(12)-0.5*LOG(MIN(YEX3MN,YEX4MN)) VINT(12)=MAX(YSTMN0,YSTMN1,YSTMN2,YSTMN3,YSTMN4,YSTMN5,YSTMN6) VINT(32)=MIN(YSTMX0,YSTMX1,YSTMX2,YSTMX3,YSTMX4,YSTMX5,YSTMX6) IF(MINT(43).EQ.1) THEN VINT(12)=-0.00001 VINT(32)=0.00001 ELSEIF(MINT(43).EQ.2) THEN VINT(12)=0.99999*YSTMX0 VINT(32)=1.00001*YSTMX0 ELSEIF(MINT(43).EQ.3) THEN VINT(12)=-1.00001*YSTMX0 VINT(32)=-0.99999*YSTMX0 ENDIF IF(VINT(32).LE.VINT(12)) MINT(51)=1 ELSEIF(ILIM.EQ.3) THEN C...Calculate limits on cos(theta-hat) YST=VINT(22) C...0) due to definition CTNMN0=-1. CTNMX0=0. CTPMN0=0. CTPMX0=1. C...1) due to explicit limits CTNMN1=MIN(0.,CKIN(27)) CTNMX1=MIN(0.,CKIN(28)) CTPMN1=MAX(0.,CKIN(27)) CTPMX1=MAX(0.,CKIN(28)) C...2) due to limits on pT-hat CTNMN2=1.-4.*PTHMIN**2/(BE34**2*TAU*VINT(2)) if (ctnmn2 .le. 0) ctnmn2 = 0 CTNMN2=-SQRT(ctnmn2) CTPMX2=-CTNMN2 CTNMX2=0. CTPMN2=0. IF(CKIN(4).GE.0.) THEN CTNMX2=-SQRT(MAX(0.,1.-4.*CKIN(4)**2/(BE34**2*TAU*VINT(2)))) CTPMN2=-CTNMX2 ENDIF C...3) due to limits on y-large and y-small CTNMN3=MIN(0.,MAX((1.+RM3-RM4)/BE34*TANH(CKIN(11)-YST), & -(1.-RM3+RM4)/BE34*TANH(CKIN(10)-YST))) CTNMX3=MIN(0.,(1.+RM3-RM4)/BE34*TANH(CKIN(12)-YST), & -(1.-RM3+RM4)/BE34*TANH(CKIN(9)-YST)) CTPMN3=MAX(0.,(1.+RM3-RM4)/BE34*TANH(CKIN(9)-YST), & -(1.-RM3+RM4)/BE34*TANH(CKIN(12)-YST)) CTPMX3=MAX(0.,MIN((1.+RM3-RM4)/BE34*TANH(CKIN(10)-YST), & -(1.-RM3+RM4)/BE34*TANH(CKIN(11)-YST))) VINT(13)=MAX(CTNMN0,CTNMN1,CTNMN2,CTNMN3) VINT(33)=MIN(CTNMX0,CTNMX1,CTNMX2,CTNMX3) VINT(14)=MAX(CTPMN0,CTPMN1,CTPMN2,CTPMN3) VINT(34)=MIN(CTPMX0,CTPMX1,CTPMX2,CTPMX3) IF(VINT(33).LE.VINT(13).AND.VINT(34).LE.VINT(14)) MINT(51)=1 ELSEIF(ILIM.EQ.4) THEN C...Calculate limits on tau' C...0) due to kinematics TAPMN0=TAU TAPMX0=1. C...1) due to explicit limits TAPMN1=CKIN(31)**2/VINT(2) TAPMX1=1. IF(CKIN(32).GE.0.) TAPMX1=CKIN(32)**2/VINT(2) VINT(16)=MAX(TAPMN0,TAPMN1) VINT(36)=MIN(TAPMX0,TAPMX1) IF(MINT(43).EQ.1) THEN VINT(16)=0.99999 VINT(36)=1.00001 ENDIF IF(VINT(36).LE.VINT(16)) MINT(51)=1 ENDIF RETURN C...Special case for low-pT and multiple interactions: C...effective kinematical limits for tau, y*, cos(theta-hat). 110 IF(ILIM.EQ.0) THEN ELSEIF(ILIM.EQ.1) THEN IF(MSTP(82).LE.1) VINT(11)=4.*PARP(81)**2/VINT(2) IF(MSTP(82).GE.2) VINT(11)=PARP(82)**2/VINT(2) VINT(31)=1. ELSEIF(ILIM.EQ.2) THEN VINT(12)=0.5*LOG(VINT(21)) VINT(32)=-VINT(12) ELSEIF(ILIM.EQ.3) THEN IF(MSTP(82).LE.1) ST2EFF=4.*PARP(81)**2/(VINT(21)*VINT(2)) IF(MSTP(82).GE.2) ST2EFF=0.01*PARP(82)**2/(VINT(21)*VINT(2)) VINT(13)=-SQRT(MAX(0.,1.-ST2EFF)) VINT(33)=0. VINT(14)=0. VINT(34)=-VINT(13) ENDIF RETURN END