ISAJET/code/zjj0.F

   1 #include "isajet/pilot.h"
   2       SUBROUTINE ZJJ0
   3 C-----------------------------------------------------------------------
   4 C
   5 C          Initialize MadGraph/Helas to generate Z + 2 jets.
   6 C          Cross section routines from MadGraph:
   7 C          ZJJ1:   q1 q1b -> Z q2 q2b, q1 != q2
   8 C          ZJJ2:   g  g   -> Z q2 q2b
   9 C          ZJJ3:   q1 q1b -> Z g  g
  10 C          ZJJ4:   q1 q1b -> Z q1 q1b
  11 C          ZJJ5:   q1 q2  -> Z q1 q2
  12 C          ZJJ6:   q1 q1  -> Z q1 q1
  13 C          ZJJ7:   g  q   -> Z g  q
  14 C
  15 C          Note: The Z is always jet1, but the other two jets are
  16 C          symmetrized so a symmetry factor of 1/2 is needed for every
  17 C          subprocess. This is included by MadGraph for identical
  18 C          particles!
  19 C
  20 C-----------------------------------------------------------------------
  21 #if defined(CERNLIB_IMPNONE)
  22       IMPLICIT NONE
  23 #endif
  24 #include "isajet/const.inc"
  25 #include "isajet/q1q2.inc"
  26 #include "isajet/itapes.inc"
  27 #include "isajet/jetlim.inc"
  28 #include "isajet/primar.inc"
  29 #include "isajet/sstype.inc"
  30 #include "isajet/mgkin.inc"
  31 #include "isajet/mgcoms.inc"
  32 #include "isajet/mgsigs.inc"
  33 C
  34       INTEGER IMAD(6)
  35       INTEGER IQ1,IQ2,IQ4,IQ5,IFL1,IFL2,IM1,IM2,I,NEV,KK,II,J
  36       REAL*8 P1(0:3),P2(0:3),P3(0:3),P4(0:3),P5(0:3)
  37       EQUIVALENCE (P1(0),PJETS8(0,1))
  38       EQUIVALENCE (P2(0),PJETS8(0,2))
  39       EQUIVALENCE (P3(0),PJETS8(0,3))
  40       EQUIVALENCE (P4(0),PJETS8(0,4))
  41       EQUIVALENCE (P5(0),PJETS8(0,5))
  42       REAL*8 WT,TERM,FJAC,SZJJ1,SZJJ2,SZJJ3,SZJJ4,SUM
  43       REAL*8 SZJJ5,SZJJ6,SZJJ7
  44       REAL X1,X2,XX,QQ,TMP(MXSIG8),QFCN,STRUC,ALQCD
  45       INTEGER IQ,IH,NPT,NNN,ISUM
  46 C
  47 C          Map Jettype/2 to MadGraph
  48       DATA IMAD/3,4,8,7,12,11/
  49 C
  50 C          Parton distributions
  51       QFCN(XX,IQ,IH)=STRUC(XX,QQ,IQ,IDIN(IH))/XX
  52 C
  53 C          Begin
  54 C
  55       NPT=MAX(NSIGMA,100)
  56       WRITE(ITLIS,1000) NTRIES,NPT
  57 1000  FORMAT(//' INITIALIZING CROSS SECTIONS WITH',I6,
  58      $' TRIES FOR',I6,' POINTS EACH:')
  59       FJAC=UNITS/SCM
  60       WTTOT8=0
  61       NSIG8=0
  62 C
  63 C          Cases 1,4: q1 q1b -> z q2 q2b
  64 C
  65       AMJET8(3)=ZMASS
  66       DO 100 IFL1=1,5
  67         IM1=IMAD(IFL1)
  68         IQ1=2*IFL1
  69         IQ2=IQ1+1
  70         AMJET8(1)=FMASS(IM1)
  71         AMJET8(2)=FMASS(IM1)
  72         DO 110 IFL2=1,6
  73           IM2=IMAD(IFL2)
  74           IQ4=2*IFL2
  75           IQ5=IQ4+1
  76           AMJET8(4)=FMASS(IM2)
  77           AMJET8(5)=FMASS(IM2)
  78 C
  79 C          Subcase 1a: 3=z, 4=q, 5=qb
  80 C
  81           IF(GOQ(IQ4,2).AND.GOQ(IQ5,3)) THEN
  82             IF(NSIG8+2.GT.MXSIG8) GO TO 999
  83             DO 120 I=1,2
  84               WTSUM8(NSIG8+I)=0
  85               WTMAX8(NSIG8+I)=0
  86               NWT8(NSIG8+I)=0
  87               IDENT8(1,NSIG8+I)=(3-2*I)*IFL1
  88               IDENT8(2,NSIG8+I)=-(3-2*I)*IFL1
  89               IDENT8(3,NSIG8+I)=IDZ
  90               IDENT8(4,NSIG8+I)=IFL2
  91               IDENT8(5,NSIG8+I)=-IFL2
  92               IF(IFL1.EQ.IFL2) THEN
  93                 IFUNC8(NSIG8+I)=4
  94               ELSE
  95                 IFUNC8(NSIG8+I)=1
  96               ENDIF
  97               NNN=0
  98               DO 125 NEV=1,NTRIES
  99                 IF(NNN.GT.NPT) GO TO 120
 100                 CALL MULJET(WT)
 101                 NWT8(NSIG8+I)=NWT8(NSIG8+I)+1
 102                 NWTTOT=NWTTOT+1
 103                 IF(WT.GT.0) THEN
 104                   NNN=NNN+1
 105                   X1=(P1(0)+P1(3))/ECM
 106                   X2=(P2(0)-P2(3))/ECM
 107                   QQ=P3(1)**2+P3(2)**2+P4(1)**2+P4(2)**2+P5(1)**2+
 108      $            P5(2)**2+AMJET8(3)**2+AMJET8(4)**2+AMJET8(5)**2
 109                   IF(I.EQ.1) THEN
 110                     IF(IFL2.EQ.IFL1) THEN
 111                       TERM=SZJJ4(P1,P2,P3,P4,P5,IM1)
 112                     ELSE
 113                       TERM=SZJJ1(P1,P2,P3,P4,P5,IM1,IM2)
 114                     ENDIF
 115                     TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 116                     TERM=TERM*WT*FJAC*QFCN(X1,IQ1,1)*QFCN(X2,IQ2,2)
 117                   ELSE
 118                     IF(IFL2.EQ.IFL1) THEN
 119                       TERM=SZJJ4(P2,P1,P3,P4,P5,IM1)
 120                     ELSE
 121                       TERM=SZJJ1(P2,P1,P3,P4,P5,IM1,IM2)
 122                     ENDIF
 123                     TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 124                     TERM=TERM*WT*FJAC*QFCN(X1,IQ2,1)*QFCN(X2,IQ1,2)
 125                   ENDIF
 126                   TERM=0.5*TERM
 127                   WTTOT8=WTTOT8+TERM
 128                   WTSUM8(NSIG8+I)=WTSUM8(NSIG8+I)+TERM
 129                   WTMAX8(NSIG8+I)=MAX(WTMAX8(NSIG8+I),TERM)
 130                 ENDIF
 131 125           CONTINUE
 132               WRITE(ITLIS,*) ' ZJJ0 WARNING: INSUFFICIENT TRIES FOR ',
 133      $        (IDENT8(KK,NSIG8+I),KK=1,5)
 134 120         CONTINUE
 135             NSIG8=NSIG8+2
 136           ENDIF
 137 C
 138 C          Subcase 1b: 3=z, 4=qb, 5=q
 139 C
 140           IF(GOQ(IQ5,2).AND.GOQ(IQ4,3)) THEN
 141             IF(NSIG8+2.GT.MXSIG8) GO TO 999
 142             DO 130 I=1,2
 143               WTSUM8(NSIG8+I)=0
 144               WTMAX8(NSIG8+I)=0
 145               NWT8(NSIG8+I)=0
 146               IDENT8(1,NSIG8+I)=(3-2*I)*IFL1
 147               IDENT8(2,NSIG8+I)=-(3-2*I)*IFL1
 148               IDENT8(3,NSIG8+I)=IDZ
 149               IDENT8(4,NSIG8+I)=-IFL2
 150               IDENT8(5,NSIG8+I)=IFL2
 151               IF(IFL1.EQ.IFL2) THEN
 152                 IFUNC8(NSIG8+I)=4
 153               ELSE
 154                 IFUNC8(NSIG8+I)=1
 155               ENDIF
 156               NNN=0
 157               DO 135 NEV=1,NTRIES
 158                 IF(NNN.GT.NPT) GO TO 130
 159                 CALL MULJET(WT)
 160                 NWT8(NSIG8+I)=NWT8(NSIG8+I)+1
 161                 NWTTOT=NWTTOT+1
 162                 IF(WT.GT.0) THEN
 163                   NNN=NNN+1
 164                   X1=(P1(0)+P1(3))/ECM
 165                   X2=(P2(0)-P2(3))/ECM
 166                   QQ=P3(1)**2+P3(2)**2+P4(1)**2+P4(2)**2+P5(1)**2+
 167      $            P5(2)**2+AMJET8(3)**2+AMJET8(4)**2+AMJET8(5)**2
 168                   IF(I.EQ.1) THEN
 169                     IF(IFL1.EQ.IFL2) THEN
 170                       TERM=SZJJ4(P1,P2,P3,P5,P4,IM1)
 171                     ELSE
 172                       TERM=SZJJ1(P1,P2,P3,P5,P4,IM1,IM2)
 173                     ENDIF
 174                     TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 175                     TERM=TERM*WT*FJAC*QFCN(X1,IQ1,1)*QFCN(X2,IQ2,2)
 176                   ELSE
 177                     IF(IFL1.EQ.IFL2) THEN
 178                       TERM=SZJJ4(P2,P1,P3,P5,P4,IM1)
 179                     ELSE
 180                       TERM=SZJJ1(P2,P1,P3,P5,P4,IM1,IM2)
 181                     ENDIF
 182                     TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 183                     TERM=TERM*WT*FJAC*QFCN(X1,IQ2,1)*QFCN(X2,IQ1,2)
 184                   ENDIF
 185                   TERM=0.5*TERM
 186                   WTTOT8=WTTOT8+TERM
 187                   WTSUM8(NSIG8+I)=WTSUM8(NSIG8+I)+TERM
 188                   WTMAX8(NSIG8+I)=MAX(WTMAX8(NSIG8+I),TERM)
 189                 ENDIF
 190 135           CONTINUE
 191               WRITE(ITLIS,*) ' ZJJ0 WARNING: INSUFFICIENT TRIES FOR ',
 192      $        (IDENT8(KK,NSIG8+I),KK=1,5)
 193 130         CONTINUE
 194             NSIG8=NSIG8+2
 195           ENDIF
 196 110     CONTINUE
 197 100   CONTINUE
 198 C
 199 C          Case 2: g g -> z q2 q2b
 200 C
 201       AMJET8(3)=ZMASS
 202       IFL1=9
 203       AMJET8(1)=0
 204       AMJET8(2)=0
 205       DO 210 IFL2=1,6
 206         IM2=IMAD(IFL2)
 207         IQ4=2*IFL2
 208         IQ5=IQ4+1
 209         AMJET8(4)=FMASS(IM2)
 210         AMJET8(5)=FMASS(IM2)
 211 C
 212 C          Subcase 2a: 3=z, 4=q, 5=qb
 213 C
 214         IF(GOQ(IQ4,2).AND.GOQ(IQ5,3)) THEN
 215           IF(NSIG8+1.GT.MXSIG8) GO TO 999
 216           WTSUM8(NSIG8+1)=0
 217           WTMAX8(NSIG8+1)=0
 218           NWT8(NSIG8+1)=0
 219           IDENT8(1,NSIG8+1)=IDGL
 220           IDENT8(2,NSIG8+1)=IDGL
 221           IDENT8(3,NSIG8+1)=IDZ
 222           IDENT8(4,NSIG8+1)=IFL2
 223           IDENT8(5,NSIG8+1)=-IFL2
 224           IFUNC8(NSIG8+1)=2
 225           NNN=0
 226           DO 225 NEV=1,NTRIES
 227             IF(NNN.GT.NPT) GO TO 220
 228             CALL MULJET(WT)
 229             NWT8(NSIG8+1)=NWT8(NSIG8+1)+1
 230             NWTTOT=NWTTOT+1
 231             IF(WT.GT.0) THEN
 232               NNN=NNN+1
 233               X1=(P1(0)+P1(3))/ECM
 234               X2=(P2(0)-P2(3))/ECM
 235               QQ=P3(1)**2+P3(2)**2+P4(1)**2+P4(2)**2+P5(1)**2+
 236      $        P5(2)**2+AMJET8(3)**2+AMJET8(4)**2+AMJET8(5)**2
 237               TERM=SZJJ2(P1,P2,P3,P4,P5,IM2)
 238               TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 239               TERM=TERM*WT*FJAC*QFCN(X1,1,1)*QFCN(X2,1,2)
 240               TERM=0.5*TERM
 241               WTTOT8=WTTOT8+TERM
 242               WTSUM8(NSIG8+1)=WTSUM8(NSIG8+1)+TERM
 243               WTMAX8(NSIG8+1)=MAX(WTMAX8(NSIG8+1),TERM)
 244             ENDIF
 245 225       CONTINUE
 246           WRITE(ITLIS,*) ' ZJJ0 WARNING: INSUFFICIENT TRIES FOR ',
 247      $    (IDENT8(KK,NSIG8+1),KK=1,5)
 248 220       CONTINUE
 249           NSIG8=NSIG8+1
 250         ENDIF
 251 C
 252 C          Subcase 2b: 3=z, 4=qb, 5=q
 253 C
 254         IF(GOQ(IQ5,2).AND.GOQ(IQ4,3)) THEN
 255           IF(NSIG8+1.GT.MXSIG8) GO TO 999
 256           WTSUM8(NSIG8+1)=0
 257           WTMAX8(NSIG8+1)=0
 258           NWT8(NSIG8+1)=0
 259           IDENT8(1,NSIG8+1)=IDGL
 260           IDENT8(2,NSIG8+1)=IDGL
 261           IDENT8(3,NSIG8+1)=IDZ
 262           IDENT8(4,NSIG8+1)=-IFL2
 263           IDENT8(5,NSIG8+1)=IFL2
 264           IFUNC8(NSIG8+1)=2
 265           NNN=0
 266           DO 235 NEV=1,NTRIES
 267             IF(NNN.GT.NPT) GO TO 230
 268             CALL MULJET(WT)
 269             NWT8(NSIG8+1)=NWT8(NSIG8+1)+1
 270             NWTTOT=NWTTOT+1
 271             IF(WT.GT.0) THEN
 272               NNN=NNN+1
 273               X1=(P1(0)+P1(3))/ECM
 274               X2=(P2(0)-P2(3))/ECM
 275               QQ=P3(1)**2+P3(2)**2+P4(1)**2+P4(2)**2+P5(1)**2+
 276      $        P5(2)**2+AMJET8(3)**2+AMJET8(4)**2+AMJET8(5)**2
 277               TERM=SZJJ2(P1,P2,P3,P5,P4,IM2)
 278               TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 279               TERM=TERM*WT*FJAC*QFCN(X1,1,1)*QFCN(X2,1,2)
 280               TERM=0.5*TERM
 281               WTTOT8=WTTOT8+TERM
 282               WTSUM8(NSIG8+1)=WTSUM8(NSIG8+1)+TERM
 283               WTMAX8(NSIG8+1)=MAX(WTMAX8(NSIG8+1),TERM)
 284             ENDIF
 285 235       CONTINUE
 286           WRITE(ITLIS,*) ' ZJJ0 WARNING: INSUFFICIENT TRIES FOR ',
 287      $    (IDENT8(KK,NSIG8+1),KK=1,5)
 288 230       CONTINUE
 289           NSIG8=NSIG8+1
 290         ENDIF
 291 210   CONTINUE
 292 C
 293 C          Case 3: q1 q1b -> z g g
 294 C
 295       AMJET8(3)=ZMASS
 296       AMJET8(4)=0
 297       AMJET8(5)=0
 298       DO 310 IFL1=1,5
 299         IM1=IMAD(IFL1)
 300         IQ1=2*IFL1
 301         IQ2=IQ1+1
 302         AMJET8(1)=FMASS(IM1)
 303         AMJET8(2)=FMASS(IM1)
 304 C
 305         IF(GOQ(1,2).AND.GOQ(1,3)) THEN
 306           IF(NSIG8+2.GT.MXSIG8) GO TO 999
 307           DO 320 I=1,2
 308             WTSUM8(NSIG8+I)=0
 309             WTMAX8(NSIG8+I)=0
 310             NWT8(NSIG8+I)=0
 311             IDENT8(1,NSIG8+I)=(3-2*I)*IFL1
 312             IDENT8(2,NSIG8+I)=-(3-2*I)*IFL1
 313             IDENT8(3,NSIG8+I)=IDZ
 314             IDENT8(4,NSIG8+I)=IDGL
 315             IDENT8(5,NSIG8+I)=IDGL
 316             IFUNC8(NSIG8+I)=3
 317             NNN=0
 318             DO 325 NEV=1,NTRIES
 319               IF(NNN.GT.NPT) GO TO 320
 320               CALL MULJET(WT)
 321               NWT8(NSIG8+I)=NWT8(NSIG8+I)+1
 322               NWTTOT=NWTTOT+1
 323               IF(WT.GT.0) THEN
 324                 NNN=NNN+1
 325                 X1=(P1(0)+P1(3))/ECM
 326                 X2=(P2(0)-P2(3))/ECM
 327                 QQ=P3(1)**2+P3(2)**2+P4(1)**2+P4(2)**2+P5(1)**2+
 328      $          P5(2)**2+AMJET8(3)**2+AMJET8(4)**2+AMJET8(5)**2
 329                 IF(I.EQ.1) THEN
 330                   TERM=SZJJ3(P1,P2,P3,P4,P5,IM1)
 331                   TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 332                   TERM=TERM*WT*FJAC*QFCN(X1,IQ1,1)*QFCN(X2,IQ2,2)
 333                 ELSE
 334                   TERM=SZJJ3(P2,P1,P3,P4,P5,IM1)
 335                   TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 336                   TERM=TERM*WT*FJAC*QFCN(X1,IQ2,1)*QFCN(X2,IQ1,2)
 337                 ENDIF
 338                 WTTOT8=WTTOT8+TERM
 339                 WTSUM8(NSIG8+I)=WTSUM8(NSIG8+I)+TERM
 340                 WTMAX8(NSIG8+I)=MAX(WTMAX8(NSIG8+I),TERM)
 341               ENDIF
 342 325         CONTINUE
 343             WRITE(ITLIS,*) ' ZJJ0 WARNING: INSUFFICIENT TRIES FOR ',
 344      $      (IDENT8(KK,NSIG8+I),KK=1,5)
 345 320       CONTINUE
 346           NSIG8=NSIG8+2
 347         ENDIF
 348 310   CONTINUE
 349 C
 350 C          Cases 5,6: q1 q2 -> Z q1 q2, q1 != q2
 351 C          Since we integrate over the Z decay, we can use the same
 352 C          cross sections for quarks (I=1) and antiquarks (I=2).
 353 C
 354       DO 400 IFL1=1,5
 355         IM1=IMAD(IFL1)
 356         DO 410 IFL2=1,5
 357           IM2=IMAD(IFL2)
 358           AMJET8(1)=FMASS(IM1)
 359           AMJET8(2)=FMASS(IM2)
 360           AMJET8(3)=ZMASS
 361           AMJET8(4)=FMASS(IM1)
 362           AMJET8(5)=FMASS(IM2)
 363           DO 420 I=1,2
 364             IQ1=2*IFL1+I-1
 365             IQ2=2*IFL2+I-1
 366             IF(GOQ(IQ1,1).AND.GOQ(IQ2,2)) THEN
 367               WTSUM8(NSIG8+1)=0
 368               WTMAX8(NSIG8+1)=0
 369               NWT8(NSIG8+1)=0
 370               IDENT8(1,NSIG8+1)=(3-2*I)*IFL1
 371               IDENT8(2,NSIG8+1)=(3-2*I)*IFL2
 372               IDENT8(3,NSIG8+1)=IDZ
 373               IDENT8(4,NSIG8+1)=(3-2*I)*IFL1
 374               IDENT8(5,NSIG8+1)=(3-2*I)*IFL2
 375               IF(IFL1.EQ.IFL2) THEN
 376                 IFUNC8(NSIG8+1)=6
 377               ELSE
 378                 IFUNC8(NSIG8+1)=5
 379               ENDIF
 380               NNN=0
 381               DO 425 NEV=1,NTRIES
 382                 IF(NNN.GT.NPT) THEN
 383                   NSIG8=NSIG8+1
 384                   GO TO 420
 385                 ENDIF
 386                 CALL MULJET(WT)
 387                 NWT8(NSIG8+1)=NWT8(NSIG8+1)+1
 388                 NWTTOT=NWTTOT+1
 389                 IF(WT.GT.0) THEN
 390                   NNN=NNN+1
 391                   X1=(P1(0)+P1(3))/ECM
 392                   X2=(P2(0)-P2(3))/ECM
 393                   QQ=P3(1)**2+P3(2)**2+P4(1)**2+P4(2)**2+P5(1)**2+
 394      $            P5(2)**2+AMJET8(3)**2+AMJET8(4)**2+AMJET8(5)**2
 395                   IF(IFL1.EQ.IFL2) THEN
 396                     TERM=SZJJ6(P1,P2,P3,P4,P5,IM1)
 397                     TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 398                     TERM=TERM*WT*FJAC*QFCN(X1,IQ1,1)*QFCN(X2,IQ2,2)
 399                   ELSE
 400                     TERM=SZJJ5(P2,P1,P3,P4,P5,IM1,IM2)
 401                     TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 402                     TERM=TERM*WT*FJAC*QFCN(X1,IQ2,1)*QFCN(X2,IQ1,2)
 403                     TERM=0.5*TERM
 404                   ENDIF
 405                   WTTOT8=WTTOT8+TERM
 406                   WTSUM8(NSIG8+1)=WTSUM8(NSIG8+1)+TERM
 407                   WTMAX8(NSIG8+1)=MAX(WTMAX8(NSIG8+1),TERM)
 408                 ENDIF
 409 425           CONTINUE
 410               WRITE(ITLIS,*) ' ZJJ0 WARNING: INSUFFICIENT TRIES FOR ',
 411      $        (IDENT8(KK,NSIG8+1),KK=1,5)
 412               NSIG8=NSIG8+1
 413             ENDIF
 414 420       CONTINUE
 415 410     CONTINUE
 416 400   CONTINUE
 417 C
 418 C          Case 7: g q -> z g q
 419 C          Since we integrate over the Z decay, we can use the same
 420 C          cross sections for quarks (I=1) and antiquarks (I=2).
 421 C
 422       DO 500 IFL2=1,5
 423         IM2=IMAD(IFL2)
 424         DO 510 I=1,2
 425           IQ5=2*IFL2+I-1
 426 C
 427 C          Subcase 7a: 3=z, 4=g, 5=q (J=1,2 for initial states)
 428 C
 429           IF(GOQ(1,2).AND.GOQ(IQ5,3)) THEN
 430             IF(NSIG8+2.GT.MXSIG8) GO TO 999
 431             AMJET8(3)=ZMASS
 432             AMJET8(4)=0
 433             AMJET8(5)=FMASS(IM2)
 434             DO 520 J=1,2
 435               WTSUM8(NSIG8+J)=0
 436               WTMAX8(NSIG8+J)=0
 437               NWT8(NSIG8+J)=0
 438               IF(J.EQ.1) THEN
 439                 IDENT8(1,NSIG8+J)=IDGL
 440                 IDENT8(2,NSIG8+J)=(3-2*I)*IFL2
 441                 IQ1=1
 442                 IQ2=IQ5
 443                 AMJET8(1)=0
 444                 AMJET8(2)=FMASS(IM2)
 445               ELSE
 446                 IDENT8(2,NSIG8+J)=IDGL
 447                 IDENT8(1,NSIG8+J)=(3-2*I)*IFL2
 448                 IQ1=IQ5
 449                 IQ2=1
 450                 AMJET8(2)=0
 451                 AMJET8(1)=FMASS(IM2)
 452               ENDIF
 453               IDENT8(3,NSIG8+J)=IDZ
 454               IDENT8(4,NSIG8+J)=IDGL
 455               IDENT8(5,NSIG8+J)=(3-2*I)*IFL2
 456               IFUNC8(NSIG8+J)=7
 457               NNN=0
 458               DO 525 NEV=1,NTRIES
 459                 IF(NNN.GT.NPT) GO TO 520
 460                 CALL MULJET(WT)
 461                 NWT8(NSIG8+J)=NWT8(NSIG8+J)+1
 462                 NWTTOT=NWTTOT+1
 463                 IF(WT.GT.0) THEN
 464                   NNN=NNN+1
 465                   X1=(P1(0)+P1(3))/ECM
 466                   X2=(P2(0)-P2(3))/ECM
 467                   QQ=P3(1)**2+P3(2)**2+P4(1)**2+P4(2)**2+P5(1)**2+
 468      $            P5(2)**2+AMJET8(3)**2+AMJET8(4)**2+AMJET8(5)**2
 469                   IF(J.EQ.1) THEN
 470                     TERM=SZJJ7(P1,P2,P3,P4,P5,IM2)
 471                   ELSE
 472                     TERM=SZJJ7(P2,P1,P3,P4,P5,IM2)
 473                   ENDIF
 474                   TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 475                   TERM=TERM*WT*FJAC*QFCN(X1,IQ1,1)*QFCN(X2,IQ2,2)
 476                   TERM=0.5*TERM
 477                   WTTOT8=WTTOT8+TERM
 478                   WTSUM8(NSIG8+J)=WTSUM8(NSIG8+J)+TERM
 479                   WTMAX8(NSIG8+J)=MAX(WTMAX8(NSIG8+J),TERM)
 480                 ENDIF
 481 525           CONTINUE
 482               WRITE(ITLIS,*) ' ZJJ0 WARNING: INSUFFICIENT TRIES FOR ',
 483      $        (IDENT8(KK,NSIG8+1),KK=1,5)
 484 520         CONTINUE
 485             NSIG8=NSIG8+2
 486           ENDIF
 487 C
 488 C          Subcase 7b: 3=z, 4=q, 5=g
 489 C
 490           IF(GOQ(IQ5,2).AND.GOQ(1,3)) THEN
 491             IF(NSIG8+2.GT.MXSIG8) GO TO 999
 492             AMJET8(3)=ZMASS
 493             AMJET8(4)=FMASS(IM2)
 494             AMJET8(5)=0
 495             DO 530 J=1,2
 496               WTSUM8(NSIG8+J)=0
 497               WTMAX8(NSIG8+J)=0
 498               NWT8(NSIG8+J)=0
 499               IF(J.EQ.1) THEN
 500                 IDENT8(1,NSIG8+J)=IDGL
 501                 IDENT8(2,NSIG8+J)=(3-2*I)*IFL2
 502                 IQ1=1
 503                 IQ2=IQ5
 504                 AMJET8(1)=0
 505                 AMJET8(2)=FMASS(IM2)
 506               ELSE
 507                 IDENT8(2,NSIG8+J)=IDGL
 508                 IDENT8(1,NSIG8+J)=(3-2*I)*IFL2
 509                 IQ1=IQ5
 510                 IQ2=1
 511                 AMJET8(2)=0
 512                 AMJET8(1)=FMASS(IM2)
 513               ENDIF
 514               IDENT8(3,NSIG8+J)=IDZ
 515               IDENT8(4,NSIG8+J)=(3-2*I)*IFL2
 516               IDENT8(5,NSIG8+J)=IDGL
 517               IFUNC8(NSIG8+J)=7
 518               NNN=0
 519               DO 535 NEV=1,NTRIES
 520                 IF(NNN.GT.NPT) GO TO 530
 521                 CALL MULJET(WT)
 522                 NWT8(NSIG8+J)=NWT8(NSIG8+J)+1
 523                 NWTTOT=NWTTOT+1
 524                 IF(WT.GT.0) THEN
 525                   NNN=NNN+1
 526                   X1=(P1(0)+P1(3))/ECM
 527                   X2=(P2(0)-P2(3))/ECM
 528                   QQ=P3(1)**2+P3(2)**2+P4(1)**2+P4(2)**2+P5(1)**2+
 529      $            P5(2)**2+AMJET8(3)**2+AMJET8(4)**2+AMJET8(5)**2
 530                   IF(J.EQ.1) THEN
 531                     TERM=SZJJ2(P1,P2,P3,P5,P4,IM2)
 532                   ELSE
 533                     TERM=SZJJ2(P2,P1,P3,P5,P4,IM2)
 534                   ENDIF
 535                   TERM=TERM*(4*PI*ALQCD(REAL(QQ)))**2
 536                   TERM=TERM*WT*FJAC*QFCN(X1,1,1)*QFCN(X2,1,2)
 537                   TERM=0.5*TERM
 538                   WTTOT8=WTTOT8+TERM
 539                   WTSUM8(NSIG8+J)=WTSUM8(NSIG8+J)+TERM
 540                   WTMAX8(NSIG8+J)=MAX(WTMAX8(NSIG8+J),TERM)
 541                 ENDIF
 542 535           CONTINUE
 543               WRITE(ITLIS,*) ' ZJJ0 WARNING: INSUFFICIENT TRIES FOR ',
 544      $        (IDENT8(KK,NSIG8+1),KK=1,5)
 545 530         CONTINUE
 546             NSIG8=NSIG8+2
 547           ENDIF
 548 510     CONTINUE
 549 500   CONTINUE
 550 C
 551 C          Sort using initial cross sections
 552 C
 553       SUM=0
 554       ISUM=0
 555       DO 991 I=1,NSIG8
 556         ISORT8(I)=NSIG8+1-I
 557         TMP(I)=WTSUM8(I)/NWT8(I)
 558         SUM=SUM+WTSUM8(I)
 559         ISUM=ISUM+NWT8(I)
 560 991   CONTINUE
 561       IF(NSIG8.GT.1) CALL SORTTF(TMP,ISORT8,NSIG8)
 562       WRITE(ITLIS,*)
 563       WRITE(ITLIS,9001)
 564 9001  FORMAT(6X,'INITIAL MULTIJET CROSS SECTIONS'/
 565      $6X,'PROCESS',18X,'SIGMA',10X,'MAX(SIGMA)')
 566       DO 992 I=1,NSIG8
 567         II=ISORT8(I)
 568         WRITE(ITLIS,9002) (IDENT8(KK,II),KK=1,5),TMP(II),WTMAX8(II)
 569 9002    FORMAT(2X,5I5,2E15.5)
 570 992   CONTINUE
 571       RETURN
 572 C
 573 C          Errors
 574 C
 575 999   WRITE(ITLIS,*) 'ERROR IN ZJJ0, NSIG8 = ',NSIG8
 576       STOP 99
 577       END