| 0795afa3 |
1 | #include "isajet/pilot.h" |
| 2 | SUBROUTINE SIGKKG |
| 3 | C |
| 4 | C Compute the KK graviton direct production cross-section |
| 5 | C d(sigma)/d(m**2)d(pT**2)d(y3)d(y4) |
| 6 | C X-sections: G.F.Giudice et al. hep-ph/9811291 |
| 7 | C Kinematics: sigdy.car (Drell-Yan + jet) |
| 8 | C |
| 9 | #if defined(CERNLIB_IMPNONE) |
| 10 | IMPLICIT NONE |
| 11 | #endif |
| 12 | C |
| 13 | #include "isajet/itapes.inc" |
| 14 | #include "isajet/qcdpar.inc" |
| 15 | #include "isajet/jetpar.inc" |
| 16 | #include "isajet/primar.inc" |
| 17 | #include "isajet/q1q2.inc" |
| 18 | #include "isajet/jetsig.inc" |
| 19 | #include "isajet/qsave.inc" |
| 20 | #include "isajet/wcon.inc" |
| 21 | #include "isajet/const.inc" |
| 22 | #include "isajet/nodcay.inc" |
| 23 | #include "isajet/kkgrav.inc" |
| 24 | C |
| 25 | REAL X(2) |
| 26 | REAL Z,S,T,U,QMW2,QZW,EHAT,Q2SAVE,YHAT,EY,P3Z,P1,P2,AMASS,ANEFF, |
| 27 | $SIG0,DENOM,QT2CUT,SIGT,SIGU,FAC,PROP,FACTOR,SIG,AMT,AMT2,SWT, |
| 28 | $P1WT,P2WT,X1WT,X2WT,TWT,UWT,Q2,QFCN,STRUC,XX,ACOSH,ATANH,P2M,P1M |
| 29 | REAL AMI2,AMF2,EFWT |
| 30 | REAL AJLWT,AJLZT1,AJLZT2,A2,A2B2,QQ,TM2 |
| 31 | INTEGER I,IQ,IH,IQ1,IFL,IQ2,IW,IQ3 |
| 32 | INTEGER NZERO(4) |
| 33 | REAL AMFAC(13) |
| 34 | INTEGER NUTYP(25) |
| 35 | INTEGER IFL1,IFL2 |
| 36 | REAL TERM |
| 37 | REAL KKGF1,KKGF2,KKGF3,SIG1,SIG2,XG,YG,F1,F2T,F2U,F3 |
| 38 | EQUIVALENCE (S,SHAT),(T,THAT),(U,UHAT),(X(1),X1) |
| 39 | C Electric charge: |
| 40 | REAL CHARGE |
| 41 | EXTERNAL CHARGE |
| 42 | C |
| 43 | C Kinematics: (Drell-Yan plus jet) |
| 44 | C |
| 45 | QMW2=QMW**2 |
| 46 | QTMW=SQRT(QMW2+QTW**2) |
| 47 | Q0W=QTMW*COSH(YW) |
| 48 | QZW=QTMW*SINH(YW) |
| 49 | QW=SQRT(QZW**2+QTW**2) |
| 50 | C Protect against errors |
| 51 | IF(QW.NE.0.) THEN |
| 52 | CTHW=QZW/QW |
| 53 | STHW=QTW/QW |
| 54 | IF(ABS(CTHW).LT.1.) THEN |
| 55 | THW=ACOS(CTHW) |
| 56 | ELSE |
| 57 | CTHW=0. |
| 58 | STHW=1. |
| 59 | THW=.5*PI |
| 60 | ENDIF |
| 61 | ELSE |
| 62 | CTHW=0. |
| 63 | STHW=1. |
| 64 | THW=.5*PI |
| 65 | ENDIF |
| 66 | c Drell-Yan plus jet |
| 67 | P3Z=P(3)*CTH(3) |
| 68 | SHAT=QMW2+2.*Q0W*P(3)-2.*QZW*P3Z+2.*PT(3)**2 |
| 69 | P1=.5*(P(3)+P3Z+Q0W+QZW) |
| 70 | P2=.5*(P(3)-P3Z+Q0W-QZW) |
| 71 | X1=P1/HALFE |
| 72 | X2=P2/HALFE |
| 73 | THAT=-2.*P1*(P(3)-P3Z) |
| 74 | UHAT=-2.*P2*(P(3)+P3Z) |
| 75 | QSQ=QTW**2 |
| 76 | QSQ=AMAX1(QSQ,4.) |
| 77 | ANEFF=4.+QSQ/(QSQ+AMASS(5)**2)+QSQ/(QSQ+AMASS(6)**2) |
| 78 | ALFQSQ=12.*PI/((33.-2.*ANEFF)*ALOG(QSQ/ALAM2)) |
| 79 | Q2SAVE=QSQ |
| 80 | QSQ=SHAT |
| 81 | C |
| 82 | C Initialize |
| 83 | C |
| 84 | SIGMA=0. |
| 85 | NSIGS=0 |
| 86 | DO 100 I=1,MXSIGS |
| 87 | SIGS(I)=0. |
| 88 | 100 CONTINUE |
| 89 | IF(X1.GE.1..OR.X2.GE.1.) RETURN |
| 90 | C |
| 91 | C Structure functions |
| 92 | C |
| 93 | DO 110 IH=1,2 |
| 94 | DO 120 IQ=1,11 |
| 95 | QSAVE(IQ,IH)=STRUC(X(IH),QSQ,IQ,IDIN(IH))/X(IH) |
| 96 | 120 CONTINUE |
| 97 | QSAVE(12,IH)=0 |
| 98 | QSAVE(13,IH)=0 |
| 99 | 110 CONTINUE |
| 100 | QSQ=Q2SAVE |
| 101 | C |
| 102 | IF((THAT/SHAT).EQ.0.) RETURN |
| 103 | IF(ABS(THAT/SHAT+1).LT.1.E-06) RETURN |
| 104 | F1=KKGF1(SHAT,THAT,QMW2) |
| 105 | F2T=KKGF2(SHAT,THAT,QMW2) |
| 106 | F2U=KKGF2(SHAT,UHAT,QMW2) |
| 107 | F3=KKGF3(SHAT,THAT,QMW2) |
| 108 | IF(F1.LE.0.OR.F2T.LE.0.OR.F2U.LE.0.OR.F3.LE.0) RETURN |
| 109 | C |
| 110 | SIG0=UNITS*0.5*KKGSD*ALFQSQ*QMW**(NEXTRAD-2)/SCM |
| 111 | C |
| 112 | C Jet 3 = gamma: |
| 113 | C |
| 114 | IF(GOQ(26,3)) THEN |
| 115 | SIG1=UNITS*0.5*KKGSD*ALFA*QMW**(NEXTRAD-2)/SCM |
| 116 | SIG1=SIG1*F1/48.0 |
| 117 | C qk + qb --> gamma + KKG |
| 118 | DO 410 IFL=1,5 |
| 119 | IQ1=2*IFL |
| 120 | IQ2=IQ1+1 |
| 121 | SIG2=SIG1*ABS(CHARGE(IFL)) |
| 122 | SIG=SIG2*QSAVE(IQ1,1)*QSAVE(IQ2,2) |
| 123 | IF(UVCUT.AND.SHAT.GE.(MASSD**2)) SIG=SIG*(MASSD**2/SHAT)**2 |
| 124 | CALL SIGFIL(SIG,IQ1,IQ2,5,26) |
| 125 | SIG=SIG2*QSAVE(IQ2,1)*QSAVE(IQ1,2) |
| 126 | IF(UVCUT.AND.SHAT.GE.(MASSD**2)) SIG=SIG*(MASSD**2/SHAT)**2 |
| 127 | CALL SIGFIL(SIG,IQ2,IQ1,5,26) |
| 128 | 410 CONTINUE |
| 129 | ENDIF |
| 130 | C |
| 131 | C Jet 3 = gluon: |
| 132 | C |
| 133 | IF(GOQ(1,3)) THEN |
| 134 | SIG1=SIG0*F1/36.0 |
| 135 | C qk + qb --> gl + KKG |
| 136 | DO 210 IFL=1,5 |
| 137 | IQ1=2*IFL |
| 138 | IQ2=IQ1+1 |
| 139 | SIG=SIG1*QSAVE(IQ1,1)*QSAVE(IQ2,2) |
| 140 | IF(UVCUT.AND.SHAT.GE.(MASSD**2)) SIG=SIG*(MASSD**2/SHAT)**2 |
| 141 | CALL SIGFIL(SIG,IQ1,IQ2,5,1) |
| 142 | SIG=SIG1*QSAVE(IQ2,1)*QSAVE(IQ1,2) |
| 143 | IF(UVCUT.AND.SHAT.GE.(MASSD**2)) SIG=SIG*(MASSD**2/SHAT)**2 |
| 144 | CALL SIGFIL(SIG,IQ1,IQ1,5,1) |
| 145 | 210 CONTINUE |
| 146 | C gl + gl --> gl + KKG |
| 147 | SIG1=SIG0*F3*3.0/16.0 |
| 148 | SIG=SIG1*QSAVE(1,1)*QSAVE(1,2) |
| 149 | IF(UVCUT.AND.SHAT.GE.(MASSD**2)) SIG=SIG*(MASSD**2/SHAT)**2 |
| 150 | CALL SIGFIL(SIG,1,1,5,1) |
| 151 | ENDIF |
| 152 | C |
| 153 | C Jet 3 = quark: |
| 154 | C |
| 155 | SIGT=SIG0*F2T/96.0 |
| 156 | SIGU=SIG0*F2U/96.0 |
| 157 | C qk + gl --> qk + KKG |
| 158 | DO 310 IQ1=2,11 |
| 159 | IQ3=IQ1 |
| 160 | IF(GOQ(IQ3,3)) THEN |
| 161 | SIG=SIGU*QSAVE(IQ1,1)*QSAVE(1,2) |
| 162 | IF(UVCUT.AND.SHAT.GE.(MASSD**2)) SIG=SIG*(MASSD**2/SHAT)**2 |
| 163 | CALL SIGFIL(SIG,IQ1,1,5,IQ3) |
| 164 | SIG=SIGT*QSAVE(IQ1,2)*QSAVE(1,1) |
| 165 | IF(UVCUT.AND.SHAT.GE.(MASSD**2)) SIG=SIG*(MASSD**2/SHAT)**2 |
| 166 | CALL SIGFIL(SIG,1,IQ1,5,IQ3) |
| 167 | ENDIF |
| 168 | 310 CONTINUE |
| 169 | C |
| 170 | RETURN |
| 171 | END |
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