HIJING/hijing1_36/hijing.F

   1 * $Id$
   2 C     Version 1.36
   3 C     Nothing important has been changed here. A few 'garbage' has been
   4 C     cleaned up here, like common block HIJJET3 for the sea quark strings
   5 C     which were originally created to implement the DPM scheme which
   6 C     later was abadoned in the final version. The lines which operate
   7 C     on these data are also deleted in the program.
   8 C
   9 C
  10 C     Version 1.35
  11 C     There are some changes in the program: subroutine HARDJET is now
  12 C     consolidated with HIJHRD. HARDJET is used to re-initiate PYTHIA
  13 C     for the triggered hard processes. Now that is done  altogether
  14 C     with other normal hard processes in modified JETINI. In the new
  15 C     version one calls JETINI every time one calls HIJHRD. In the new
  16 C     version the effect of the isospin of the nucleon on hard processes,
  17 C     especially direct photons is correctly considered.
  18 C     For A+A collisions, one has to initilize pythia
  19 C     separately for each type of collisions, pp, pn,np and nn,
  20 C     or hp and hn for hA collisions. In JETINI we use the following
  21 C     catalogue for different types of collisions:
  22 C     h+h: h+h (I_TYPE=1)
  23 C     h+A: h+p (I_TYPE=1), h+n (I_TYPE=2)
  24 C     A+h: p+h (I_TYPE=1), n+h (I_TYPE=2)
  25 C     A+A: p+p (I_TYPE=1), p+n (I_TYPE=2), n+p (I_TYPE=3), n+n (I_TYPE=4)
  26 C*****************************************************************
  27 c
  28 C
  29 C     Version 1.34
  30 C     Last modification on January 5, 1998. Two misstakes are corrected in
  31 C     function G. A Misstake in the subroutine Parton is also corrected.
  32 C     (These are pointed out by Ysushi Nara).
  33 C
  34 C
  35 C       Last modifcation on April 10, 1996. To conduct final
  36 C       state radiation, PYTHIA reorganize the two scattered
  37 C       partons and their final momenta will be a little
  38 C       different. The summed total momenta of the partons
  39 C       from the final state radiation are stored in HINT1(26-29)
  40 C       and HINT1(36-39) which are little different from
  41 C       HINT1(21-24) and HINT1(41-44).
  42 C
  43 C       Version 1.33
  44 C
  45 C       Last modfication  on September 11, 1995. When HIJING and
  46 C       PYTHIA are initialized, the shadowing is evaluated at
  47 C       b=0 which is the maximum. This will cause overestimate
  48 C       of shadowing for peripheral interactions. To correct this
  49 C       problem, shadowing is set to zero when initializing. Then
  50 C       use these maximum  cross section without shadowing as a
  51 C       normalization of the Monte Carlo. This however increase
  52 C       the computing time. IHNT2(16) is used to indicate whether
  53 C       the sturcture function is called for (IHNT2(16)=1) initialization
  54 C       or for (IHNT2(16)=0)normal collisions simulation
  55 C
  56 C       Last modification on Aagust 28, 1994. Two bugs associate
  57 C       with the impact parameter dependence of the shadowing is
  58 C       corrected.
  59 C
  60 C
  61 c       Last modification on October 14, 1994. One bug is corrected
  62 c       in the direct photon production option in subroutine
  63 C       HIJHRD.( this problem was reported by Jim Carroll and Mike Beddo).
  64 C       Another bug associated with keeping the decay history
  65 C       in the particle information is also corrected.(this problem
  66 C       was reported by Matt Bloomer)
  67 C
  68 C
  69 C       Last modification on July 15, 1994. The option to trig on
  70 C       heavy quark production (charm IHPR2(18)=0 or beauty IHPR2(18)=1)
  71 C       is added. To do this, set IHPR2(3)=3. For inclusive production,
  72 C       one should reset HIPR1(10)=0.0. One can also trig larger pt
  73 C       QQbar production by giving HIPR1(10) a nonvanishing value.
  74 C       The mass of the heavy quark in the calculation of the cross
  75 C       section (HINT1(59)--HINT1(65)) is given by HIPR1(7) (the
  76 C       default is the charm mass D=1.5). We also include a separate
  77 C       K-factor for heavy quark and direct photon production by
  78 C       HIPR1(23)(D=2.0).
  79 C
  80 C       Last modification on May 24, 1994.  The option to
  81 C       retain the information of all particles including those
  82 C       who have decayed is IHPR(21)=1 (default=0). KATT(I,3) is
  83 C       added to contain the line number of the parent particle
  84 C       of the current line which is produced via a decay.
  85 C       KATT(I,4) is the status number of the particle: 11=particle
  86 C       which has decayed; 1=finally produced particle.
  87 C
  88 C
  89 C       Last modification on May 24, 1994( in HIJSFT when valence quark
  90 C       is quenched, the following error is corrected. 1.2*IHNT2(1) -->
  91 C       1.2*IHNT2(1)**0.333333, 1.2*IHNT2(3) -->1.2*IHNT(3)**0.333333)
  92 C
  93 C
  94 C       Last modification on March 16, 1994 (heavy flavor production
  95 C       processes MSUB(81)=1 MSUB(82)=1 have been switched on,
  96 C       charm production is the default, B-quark option is
  97 C       IHPR2(18), when it is switched on, charm quark is
  98 C       automatically off)
  99 C
 100 C
 101 C       Last modification on March 23, 1994 (an error is corrected
 102 C       in the impact parameter dependence of the jet cross section)
 103 C
 104 C       Last modification Oct. 1993 to comply with non-vax
 105 C       machines' compiler
 106 C
 107 C*********************************************
 108 C       LAST MODIFICATION April 5, 1991
 109 CQUARK DISTRIBUTIOIN (1-X)**A/(X**2+C**2/S)**B
 110 C(A=HIPR1(44),B=HIPR1(46),C=HIPR1(45))
 111 C STRING FLIP, VENUS OPTION IHPR2(15)=1,IN WHICH ONE CAN HAVE ONE AND
 112 C TWO COLOR CHANGES, (1-W)**2,W*(1-W),W*(1-W),AND W*2, W=HIPR1(18),
 113 C AMONG PT DISTRIBUTION OF SEA QUARKS IS CONTROLLED BY HIPR1(42)
 114 C
 115 C       gluon jets can form a single string system
 116 C
 117 C       initial state radiation is included
 118 C
 119 C       all QCD subprocesses are included
 120 c
 121 c       direct particles production is included(currently only direct
 122 C               photon)
 123 c
 124 C       Effect of high P_T trigger bias on multiple jets distribution
 125 c
 126 C******************************************************************
 127 C                               HIJING.10                         *
 128 C                 Heavy Ion Jet INteraction Generator             *
 129 C                                  by                             *
 130 C                  X. N. Wang      and   M. Gyulassy              *
 131 C                     Lawrence Berkeley Laboratory                *
 132 C                                                                 *
 133 C******************************************************************
 134 C
 135 C******************************************************************
 136 C NFP(K,1),NFP(K,2)=flavor of q and di-q, NFP(K,3)=present ID of  *
 137 C proj, NFP(K,4) original ID of proj.  NFP(K,5)=colli status(0=no,*
 138 C 1=elastic,2=the diffrac one in single-diffrac,3= excited string.*
 139 C |NFP(K,6)| is the total # of jet production, if NFP(K,6)<0 it   *
 140 C can not produce jet anymore. NFP(K,10)=valence quarks scattering*
 141 C (0=has not been,1=is going to be, -1=has already been scattered *
 142 C NFP(k,11) total number of interactions this proj has suffered   *
 143 C PP(K,1)=PX,PP(K,2)=PY,PP(K,3)=PZ,PP(K,4)=E,PP(K,5)=M(invariant  *
 144 C mass), PP(K,6,7),PP(K,8,9)=transverse momentum of quark and     *
 145 C diquark,PP(K,10)=PT of the hard scattering between the valence  *
 146 C quarks; PP(K,14,15)=the mass of quark,diquark.                  *
 147 C******************************************************************
 148 C
 149 C****************************************************************
 150 C
 151 C       SUBROUTINE HIJING
 152 C
 153 C****************************************************************
 154         SUBROUTINE HIJING(FRAME,BMIN0,BMAX0)
 155         CHARACTER FRAME*8
 156         DIMENSION SCIP(300,300),RNIP(300,300),SJIP(300,300),JTP(3),
 157      &                  IPCOL(90000),ITCOL(90000)
 158 #define BLANKET_SAVE
 159 #include "hiparnt.inc"
 160 C
 161 #include "hijcrdn.inc"
 162 #include "hijglbr.inc"
 163 #include "himain1.inc"
 164 #include "himain2.inc"
 165 #include "histrng.inc"
 166 #include "hijjet1.inc"
 167 #include "hijjet2.inc"
 168 #include "hijjet4.inc"
 169 C
 170 #include "lujets_hijing.inc"
 171 #include "ludat1_hijing.inc"
 172         SAVE
 173
 174         BMAX=MIN(BMAX0,HIPR1(34)+HIPR1(35))
 175         BMIN=MIN(BMIN0,BMAX)
 176         IF(IHNT2(1).LE.1 .AND. IHNT2(3).LE.1) THEN
 177                 BMIN=0.0
 178                 BMAX=2.5*SQRT(HIPR1(31)*0.1/HIPR1(40))
 179         ENDIF
 180 C                       ********HIPR1(31) is in mb =0.1fm**2
 181 C*******THE FOLLOWING IS TO SELECT THE COORDINATIONS OF NUCLEONS
 182 C       BOTH IN PROJECTILE AND TARGET NUCLEAR( in fm)
 183 C
 184         YP(1,1)=0.0
 185         YP(2,1)=0.0
 186         YP(3,1)=0.0
 187         IF(IHNT2(1).LE.1) GO TO 14
 188         DO 10 KP=1,IHNT2(1)
 189 5       R=HIRND(1)
 190         X=RLU_HIJING(0)
 191         CX=2.0*X-1.0
 192         SX=SQRT(1.0-CX*CX)
 193 C               ********choose theta from uniform cos(theta) distr
 194         PHI=RLU_HIJING(0)*2.0*HIPR1(40)
 195 C               ********choose phi form uniform phi distr 0 to 2*pi
 196         YP(1,KP)=R*SX*COS(PHI)
 197         YP(2,KP)=R*SX*SIN(PHI)
 198         YP(3,KP)=R*CX
 199         IF(HIPR1(29).EQ.0.0) GO TO 10
 200         DO 8  KP2=1,KP-1
 201                 DNBP1=(YP(1,KP)-YP(1,KP2))**2
 202                 DNBP2=(YP(2,KP)-YP(2,KP2))**2
 203                 DNBP3=(YP(3,KP)-YP(3,KP2))**2
 204                 DNBP=DNBP1+DNBP2+DNBP3
 205                 IF(DNBP.LT.HIPR1(29)*HIPR1(29)) GO TO 5
 206 C                       ********two neighbors cannot be closer than
 207 C                               HIPR1(29)
 208 8       CONTINUE
 209 10      CONTINUE
 210         DO 12 I=1,IHNT2(1)-1
 211         DO 12 J=I+1,IHNT2(1)
 212         IF(YP(3,I).GT.YP(3,J)) GO TO 12
 213         Y1=YP(1,I)
 214         Y2=YP(2,I)
 215         Y3=YP(3,I)
 216         YP(1,I)=YP(1,J)
 217         YP(2,I)=YP(2,J)
 218         YP(3,I)=YP(3,J)
 219         YP(1,J)=Y1
 220         YP(2,J)=Y2
 221         YP(3,J)=Y3
 222 12      CONTINUE
 223 C
 224 C******************************
 225 14      YT(1,1)=0.0
 226         YT(2,1)=0.0
 227         YT(3,1)=0.0
 228         IF(IHNT2(3).LE.1) GO TO 24
 229         DO 20 KT=1,IHNT2(3)
 230 15      R=HIRND(2)
 231         X=RLU_HIJING(0)
 232         CX=2.0*X-1.0
 233         SX=SQRT(1.0-CX*CX)
 234 C               ********choose theta from uniform cos(theta) distr
 235         PHI=RLU_HIJING(0)*2.0*HIPR1(40)
 236 C               ********chose phi form uniform phi distr 0 to 2*pi
 237         YT(1,KT)=R*SX*COS(PHI)
 238         YT(2,KT)=R*SX*SIN(PHI)
 239         YT(3,KT)=R*CX
 240         IF(HIPR1(29).EQ.0.0) GO TO 20
 241         DO 18  KT2=1,KT-1
 242                 DNBT1=(YT(1,KT)-YT(1,KT2))**2
 243                 DNBT2=(YT(2,KT)-YT(2,KT2))**2
 244                 DNBT3=(YT(3,KT)-YT(3,KT2))**2
 245                 DNBT=DNBT1+DNBT2+DNBT3
 246                 IF(DNBT.LT.HIPR1(29)*HIPR1(29)) GO TO 15
 247 C                       ********two neighbors cannot be closer than
 248 C                               HIPR1(29)
 249 18      CONTINUE
 250 20      CONTINUE
 251         DO 22 I=1,IHNT2(3)-1
 252         DO 22 J=I+1,IHNT2(3)
 253         IF(YT(3,I).LT.YT(3,J)) GO TO 22
 254         Y1=YT(1,I)
 255         Y2=YT(2,I)
 256         Y3=YT(3,I)
 257         YT(1,I)=YT(1,J)
 258         YT(2,I)=YT(2,J)
 259         YT(3,I)=YT(3,J)
 260         YT(1,J)=Y1
 261         YT(2,J)=Y2
 262         YT(3,J)=Y3
 263 22      CONTINUE
 264
 265 C********************
 266 24      MISS=-1
 267
 268 50      MISS=MISS+1
 269         IF(MISS.GT.50) THEN
 270            WRITE(6,*) 'infinite loop happened in  HIJING'
 271            STOP
 272         ENDIF
 273
 274         NATT=0
 275         JATT=0
 276         EATT=0.0
 277         CALL HIJINI
 278         NLOP=0
 279 C                       ********Initialize for a new event
 280 60      NT=0
 281         NP=0
 282         N0=0
 283         N01=0
 284         N10=0
 285         N11=0
 286         NELT=0
 287         NINT=0
 288         NELP=0
 289         NINP=0
 290         NSG=0
 291         NCOLT=0
 292
 293 C****   BB IS THE ABSOLUTE VALUE OF IMPACT PARAMETER,BB**2 IS
 294 C       RANDOMLY GENERATED AND ITS ORIENTATION IS RANDOMLY SET
 295 C       BY THE ANGLE PHI  FOR EACH COLLISION.******************
 296 C
 297         BB=SQRT(BMIN**2+RLU_HIJING(0)*(BMAX**2-BMIN**2))
 298         PHI=2.0*HIPR1(40)*RLU_HIJING(0)
 299         BBX=BB*COS(PHI)
 300         BBY=BB*SIN(PHI)
 301         HINT1(19)=BB
 302         HINT1(20)=PHI
 303 C
 304         DO 70 JP=1,IHNT2(1)
 305         DO 70 JT=1,IHNT2(3)
 306            SCIP(JP,JT)=-1.0
 307            B2=(YP(1,JP)+BBX-YT(1,JT))**2+(YP(2,JP)+BBY-YT(2,JT))**2
 308            R2=B2*HIPR1(40)/HIPR1(31)/0.1
 309 C               ********mb=0.1*fm, YP is in fm,HIPR1(31) is in mb
 310            RRB1=MIN((YP(1,JP)**2+YP(2,JP)**2)
 311      &          /1.2**2/REAL(IHNT2(1))**0.6666667,1.0)
 312            RRB2=MIN((YT(1,JT)**2+YT(2,JT)**2)
 313      &          /1.2**2/REAL(IHNT2(3))**0.6666667,1.0)
 314            APHX1=HIPR1(6)*4.0/3.0*(IHNT2(1)**0.3333333-1.0)
 315      &           *SQRT(1.0-RRB1)
 316            APHX2=HIPR1(6)*4.0/3.0*(IHNT2(3)**0.3333333-1.0)
 317      &           *SQRT(1.0-RRB2)
 318            HINT1(18)=HINT1(14)-APHX1*HINT1(15)
 319      &                  -APHX2*HINT1(16)+APHX1*APHX2*HINT1(17)
 320            IF(IHPR2(14).EQ.0.OR.
 321      &          (IHNT2(1).EQ.1.AND.IHNT2(3).EQ.1)) THEN
 322               GS=1.0-EXP(-(HIPR1(30)+HINT1(18))*ROMG(R2)/HIPR1(31))
 323               RANTOT=RLU_HIJING(0)
 324               IF(RANTOT.GT.GS) GO TO 70
 325               GO TO 65
 326            ENDIF
 327            GSTOT_0=2.0*(1.0-EXP(-(HIPR1(30)+HINT1(18))
 328      &             /HIPR1(31)/2.0*ROMG(0.0)))
 329            R2=R2/GSTOT_0
 330            GS=1.0-EXP(-(HIPR1(30)+HINT1(18))/HIPR1(31)*ROMG(R2))
 331            GSTOT=2.0*(1.0-SQRT(1.0-GS))
 332            RANTOT=RLU_HIJING(0)*GSTOT_0
 333            IF(RANTOT.GT.GSTOT) GO TO 70
 334            IF(RANTOT.GT.GS) THEN
 335               CALL HIJCSC(JP,JT)
 336               GO TO 70
 337 C                       ********perform elastic collisions
 338            ENDIF
 339  65        SCIP(JP,JT)=R2
 340            RNIP(JP,JT)=RANTOT
 341            SJIP(JP,JT)=HINT1(18)
 342            NCOLT=NCOLT+1
 343            IPCOL(NCOLT)=JP
 344            ITCOL(NCOLT)=JT
 345 70      CONTINUE
 346 C               ********total number interactions proj and targ has
 347 C                               suffered
 348         IF(NCOLT.EQ.0) THEN
 349            NLOP=NLOP+1
 350            IF(NLOP.LE.20.OR.
 351      &           (IHNT2(1).EQ.1.AND.IHNT2(3).EQ.1)) GO TO 60
 352
 353
 354            RETURN
 355         ENDIF
 356 C               ********At large impact parameter, there maybe no
 357 C                       interaction at all. For NN collision
 358 C                       repeat the event until interaction happens
 359 C
 360         IF(IHPR2(3).NE.0) THEN
 361            NHARD=1+INT(RLU_HIJING(0)*(NCOLT-1)+0.5)
 362            NHARD=MIN(NHARD,NCOLT)
 363            JPHARD=IPCOL(NHARD)
 364            JTHARD=ITCOL(NHARD)
 365         ENDIF
 366 C
 367         IF(IHPR2(9).EQ.1) THEN
 368                 NMINI=1+INT(RLU_HIJING(0)*(NCOLT-1)+0.5)
 369                 NMINI=MIN(NMINI,NCOLT)
 370                 JPMINI=IPCOL(NMINI)
 371                 JTMINI=ITCOL(NMINI)
 372         ENDIF
 373 C               ********Specifying the location of the hard and
 374 C                       minijet if they are enforced by user
 375 C
 376         DO 200 JP=1,IHNT2(1)
 377         DO 200 JT=1,IHNT2(3)
 378         IF(SCIP(JP,JT).EQ.-1.0) GO TO 200
 379                 NFP(JP,11)=NFP(JP,11)+1
 380                 NFT(JT,11)=NFT(JT,11)+1
 381         IF(NFP(JP,5).LE.1 .AND. NFT(JT,5).GT.1) THEN
 382                 NP=NP+1
 383                 N01=N01+1
 384         ELSE IF(NFP(JP,5).GT.1 .AND. NFT(JT,5).LE.1) THEN
 385                 NT=NT+1
 386                 N10=N10+1
 387         ELSE IF(NFP(JP,5).LE.1 .AND. NFT(JT,5).LE.1) THEN
 388                 NP=NP+1
 389                 NT=NT+1
 390                 N0=N0+1
 391         ELSE IF(NFP(JP,5).GT.1 .AND. NFT(JT,5).GT.1) THEN
 392                 N11=N11+1
 393         ENDIF
 394         JOUT=0
 395         NFP(JP,10)=0
 396         NFT(JT,10)=0
 397 C*****************************************************************
 398         IF(IHPR2(8).EQ.0 .AND. IHPR2(3).EQ.0) GO TO 160
 399 C               ********When IHPR2(8)=0 no jets are produced
 400         IF(NFP(JP,6).LT.0 .OR. NFT(JT,6).LT.0) GO TO 160
 401 C               ********jets can not be produced for (JP,JT)
 402 C                       because not enough energy avaible for
 403 C                               JP or JT
 404         R2=SCIP(JP,JT)
 405         HINT1(18)=SJIP(JP,JT)
 406         TT=ROMG(R2)*HINT1(18)/HIPR1(31)
 407         TTS=HIPR1(30)*ROMG(R2)/HIPR1(31)
 408         NJET=0
 409         IF(IHPR2(3).NE.0 .AND. JP.EQ.JPHARD .AND. JT.EQ.JTHARD) THEN
 410            CALL JETINI(JP,JT,1)
 411            CALL HIJHRD(JP,JT,0,JFLG,0)
 412            HINT1(26)=HINT1(47)
 413            HINT1(27)=HINT1(48)
 414            HINT1(28)=HINT1(49)
 415            HINT1(29)=HINT1(50)
 416            HINT1(36)=HINT1(67)
 417            HINT1(37)=HINT1(68)
 418            HINT1(38)=HINT1(69)
 419            HINT1(39)=HINT1(70)
 420 C
 421            IF(ABS(HINT1(46)).GT.HIPR1(11).AND.JFLG.EQ.2) NFP(JP,7)=1
 422            IF(ABS(HINT1(56)).GT.HIPR1(11).AND.JFLG.EQ.2) NFT(JT,7)=1
 423            IF(MAX(ABS(HINT1(46)),ABS(HINT1(56))).GT.HIPR1(11).AND.
 424      &                          JFLG.GE.3) IASG(NSG,3)=1
 425            IHNT2(9)=IHNT2(14)
 426            IHNT2(10)=IHNT2(15)
 427            DO 105 I05=1,5
 428               HINT1(20+I05)=HINT1(40+I05)
 429               HINT1(30+I05)=HINT1(50+I05)
 430  105       CONTINUE
 431            JOUT=1
 432            IF(IHPR2(8).EQ.0) GO TO 160
 433            RRB1=MIN((YP(1,JP)**2+YP(2,JP)**2)/1.2**2
 434      &          /REAL(IHNT2(1))**0.6666667,1.0)
 435            RRB2=MIN((YT(1,JT)**2+YT(2,JT)**2)/1.2**2
 436      &          /REAL(IHNT2(3))**0.6666667,1.0)
 437            APHX1=HIPR1(6)*4.0/3.0*(IHNT2(1)**0.3333333-1.0)
 438      &           *SQRT(1.0-RRB1)
 439            APHX2=HIPR1(6)*4.0/3.0*(IHNT2(3)**0.3333333-1.0)
 440      &           *SQRT(1.0-RRB2)
 441            HINT1(65)=HINT1(61)-APHX1*HINT1(62)
 442      &                  -APHX2*HINT1(63)+APHX1*APHX2*HINT1(64)
 443            TTRIG=ROMG(R2)*HINT1(65)/HIPR1(31)
 444            NJET=-1
 445 C               ********subtract the trigger jet from total number
 446 C                       of jet production  to be done since it has
 447 C                               already been produced here
 448            XR1=-ALOG(EXP(-TTRIG)+RLU_HIJING(0)*(1.0-EXP(-TTRIG)))
 449  106       NJET=NJET+1
 450            XR1=XR1-ALOG(RLU_HIJING(0))
 451            IF(XR1.LT.TTRIG) GO TO 106
 452            XR=0.0
 453  107       NJET=NJET+1
 454            XR=XR-ALOG(RLU_HIJING(0))
 455            IF(XR.LT.TT-TTRIG) GO TO 107
 456            NJET=NJET-1
 457            GO TO 112
 458         ENDIF
 459 C               ********create a hard interaction with specified P_T
 460 c                                when IHPR2(3)>0
 461         IF(IHPR2(9).EQ.1.AND.JP.EQ.JPMINI.AND.JT.EQ.JTMINI) GO TO 110
 462 C               ********create at least one pair of mini jets
 463 C                       when IHPR2(9)=1
 464 C
 465         IF(IHPR2(8).GT.0 .AND.RNIP(JP,JT).LT.EXP(-TT)*
 466      &          (1.0-EXP(-TTS))) GO TO 160
 467 C               ********this is the probability for no jet production
 468 110     XR=-ALOG(EXP(-TT)+RLU_HIJING(0)*(1.0-EXP(-TT)))
 469 111     NJET=NJET+1
 470         XR=XR-ALOG(RLU_HIJING(0))
 471         IF(XR.LT.TT) GO TO 111
 472 112     NJET=MIN(NJET,IHPR2(8))
 473         IF(IHPR2(8).LT.0)  NJET=ABS(IHPR2(8))
 474 C               ******** Determine number of mini jet production
 475 C
 476         DO 150 I_JET=1,NJET
 477            CALL JETINI(JP,JT,0)
 478            CALL HIJHRD(JP,JT,JOUT,JFLG,1)
 479 C               ********JFLG=1 jets valence quarks, JFLG=2 with
 480 C                       gluon jet, JFLG=3 with q-qbar prod for
 481 C                       (JP,JT). If JFLG=0 jets can not be produced
 482 C                       this time. If JFLG=-1, error occured abandon
 483 C                       this event. JOUT is the total hard scat for
 484 C                       (JP,JT) up to now.
 485            IF(JFLG.EQ.0) GO TO 160
 486            IF(JFLG.LT.0) THEN
 487               IF(IHPR2(10).NE.0) WRITE(6,*) 'error occured in HIJHRD'
 488               GO TO 50
 489            ENDIF
 490            JOUT=JOUT+1
 491            IF(ABS(HINT1(46)).GT.HIPR1(11).AND.JFLG.EQ.2) NFP(JP,7)=1
 492            IF(ABS(HINT1(56)).GT.HIPR1(11).AND.JFLG.EQ.2) NFT(JT,7)=1
 493            IF(MAX(ABS(HINT1(46)),ABS(HINT1(56))).GT.HIPR1(11).AND.
 494      &                  JFLG.GE.3) IASG(NSG,3)=1
 495 C               ******** jet with PT>HIPR1(11) will be quenched
 496  150    CONTINUE
 497  160    CONTINUE
 498         CALL HIJSFT(JP,JT,JOUT,IERROR)
 499         IF(IERROR.NE.0) THEN
 500            IF(IHPR2(10).NE.0) WRITE(6,*) 'error occured in HIJSFT'
 501            GO TO 50
 502         ENDIF
 503 C
 504 C               ********conduct soft scattering between JP and JT
 505         JATT=JATT+JOUT
 506
 507 200     CONTINUE
 508
 509 c
 510 c**************************
 511 c
 512         DO 201 JP=1,IHNT2(1)
 513            IF(NFP(JP,5).GT.2) THEN
 514               NINP=NINP+1
 515            ELSE IF(NFP(JP,5).EQ.2.OR.NFP(JP,5).EQ.1) THEN
 516               NELP=NELP+1
 517            ENDIF
 518  201    continue
 519         DO 202 JT=1,IHNT2(3)
 520            IF(NFT(JT,5).GT.2) THEN
 521               NINT=NINT+1
 522            ELSE IF(NFT(JT,5).EQ.2.OR.NFT(JT,5).EQ.1) THEN
 523               NELT=NELT+1
 524            ENDIF
 525  202    continue
 526 c
 527 c*******************************
 528
 529 C********perform jet quenching for jets with PT>HIPR1(11)**********
 530
 531         IF((IHPR2(8).NE.0.OR.IHPR2(3).NE.0).AND.IHPR2(4).GT.0.AND.
 532      &                  IHNT2(1).GT.1.AND.IHNT2(3).GT.1) THEN
 533                 DO 271 I=1,IHNT2(1)
 534                         IF(NFP(I,7).EQ.1) CALL QUENCH(I,1)
 535 271             CONTINUE
 536                 DO 272 I=1,IHNT2(3)
 537                         IF(NFT(I,7).EQ.1) CALL QUENCH(I,2)
 538 272             CONTINUE
 539                 DO 273 ISG=1,NSG
 540                         IF(IASG(ISG,3).EQ.1) CALL QUENCH(ISG,3)
 541 273             CONTINUE
 542         ENDIF
 543 C
 544 C**************fragment all the string systems in the following*****
 545 C
 546 C********N_ST is where particle information starts
 547 C********N_STR+1 is the number of strings in fragmentation
 548 C********the number of strings before a line is stored in K(I,4)
 549 C********IDSTR is id number of the string system (91,92 or 93)
 550 C
 551         IF(IHPR2(20).NE.0) THEN
 552            DO 360 ISG=1,NSG
 553                 CALL HIJFRG(ISG,3,IERROR)
 554                 IF(MSTU(24).NE.0 .OR.IERROR.GT.0) THEN
 555                    MSTU(24)=0
 556                    MSTU(28)=0
 557                    IF(IHPR2(10).NE.0) THEN
 558                       call LULIST_HIJING(1)
 559                       WRITE(6,*) 'error occured, repeat the event'
 560                    ENDIF
 561                    GO TO 50
 562                 ENDIF
 563 C                       ********Check errors
 564 C
 565                 N_ST=1
 566                 IDSTR=92
 567                 IF(IHPR2(21).EQ.0) THEN
 568                    CALL LUEDIT_HIJING(2)
 569                 ELSE
 570 351                N_ST=N_ST+1
 571                    IF(K(N_ST,2).LT.91.OR.K(N_ST,2).GT.93) GO TO  351
 572                    IDSTR=K(N_ST,2)
 573                    N_ST=N_ST+1
 574                 ENDIF
 575 C
 576                 IF(FRAME.EQ.'LAB') THEN
 577                         CALL HIBOOST
 578                 ENDIF
 579 C               ******** boost back to lab frame(if it was in)
 580 C
 581                 N_STR=0
 582                 DO 360 I=N_ST,N
 583                    IF(K(I,2).EQ.IDSTR) THEN
 584                       N_STR=N_STR+1
 585                       GO TO 360
 586                    ENDIF
 587                    K(I,4)=N_STR
 588                    NATT=NATT+1
 589                    KATT(NATT,1)=K(I,2)
 590                    KATT(NATT,2)=20
 591                    KATT(NATT,4)=K(I,1)
 592                    IF(K(I,3).EQ.0 .OR. K(K(I,3),2).EQ.IDSTR) THEN
 593                       KATT(NATT,3)=0
 594                    ELSE
 595                       KATT(NATT,3)=NATT-I+K(I,3)+N_STR-K(K(I,3),4)
 596                    ENDIF
 597 C       ****** identify the mother particle
 598                    PATT(NATT,1)=P(I,1)
 599                    PATT(NATT,2)=P(I,2)
 600                    PATT(NATT,3)=P(I,3)
 601                    PATT(NATT,4)=P(I,4)
 602                    VATT(NATT,1)=V(I,1)
 603                    VATT(NATT,2)=V(I,2)
 604                    VATT(NATT,3)=V(I,3)
 605                    VATT(NATT,4)=V(I,4)
 606
 607                    EATT=EATT+P(I,4)
 608 360        CONTINUE
 609 C               ********Fragment the q-qbar jets systems *****
 610 C
 611            JTP(1)=IHNT2(1)
 612            JTP(2)=IHNT2(3)
 613            DO 400 NTP=1,2
 614            DO 400 J_JTP=1,JTP(NTP)
 615                 CALL HIJFRG(J_JTP,NTP,IERROR)
 616                 IF(MSTU(24).NE.0 .OR. IERROR.GT.0) THEN
 617                    MSTU(24)=0
 618                    MSTU(28)=0
 619                    IF(IHPR2(10).NE.0) THEN
 620                       call LULIST_HIJING(1)
 621                       WRITE(6,*) 'error occured, repeat the event'
 622                    ENDIF
 623                    GO TO 50
 624                 ENDIF
 625 C                       ********check errors
 626 C
 627                 N_ST=1
 628                 IDSTR=92
 629
 630                 NFTP=NFP(J_JTP,5)
 631                 IF(NTP.EQ.2) NFTP=10+NFT(J_JTP,5)
 632
 633                 IF(IHPR2(21).EQ.0) THEN
 634                    CALL LUEDIT_HIJING(2)
 635                 ELSE IF (NFTP.EQ. 3 .OR. NFTP .EQ. 13) THEN
 636 381                N_ST=N_ST+1
 637                    IF(K(N_ST,2).LT.91.OR.K(N_ST,2).GT.93) GO TO  381
 638                    IDSTR=K(N_ST,2)
 639                    N_ST=N_ST+1
 640                 ENDIF
 641                 IF(FRAME.EQ.'LAB') THEN
 642                         CALL HIBOOST
 643                 ENDIF
 644 C               ******** boost back to lab frame(if it was in)
 645 C
 646                 N_STR=0
 647                 DO 390 I=N_ST,N
 648                    IF(K(I,2).EQ.IDSTR) THEN
 649                       N_STR=N_STR+1
 650                       GO TO 390
 651                    ENDIF
 652                    K(I,4)=N_STR
 653                    NATT=NATT+1
 654                    KATT(NATT,1)=K(I,2)
 655                    KATT(NATT,2)=NFTP
 656                    KATT(NATT,4)=K(I,1)
 657                    IF(K(I,3).EQ.0 ) THEN
 658                       KATT(NATT,3)=0
 659                    ELSE
 660                       IF(K(K(I,3),2).EQ.IDSTR) THEN
 661                          KATT(NATT,3)=0
 662                       ELSE
 663                          KATT(NATT,3)=NATT-I+K(I,3)+N_STR-K(K(I,3),4)
 664                       ENDIF
 665                    ENDIF
 666 C       ****** identify the mother particle
 667                    PATT(NATT,1)=P(I,1)
 668                    PATT(NATT,2)=P(I,2)
 669                    PATT(NATT,3)=P(I,3)
 670                    PATT(NATT,4)=P(I,4)
 671                    VATT(NATT,1)=V(I,1)
 672                    VATT(NATT,2)=V(I,2)
 673                    VATT(NATT,3)=V(I,3)
 674                    VATT(NATT,4)=V(I,4)
 675
 676                    EATT=EATT+P(I,4)
 677 390             CONTINUE
 678 400        CONTINUE
 679 C               ********Fragment the q-qq related string systems
 680         ENDIF
 681
 682         DO 450 I=1,NDR
 683                 NATT=NATT+1
 684                 KATT(NATT,1)=KFDR(I)
 685                 KATT(NATT,2)=40
 686                 KATT(NATT,3)=0
 687                 PATT(NATT,1)=PDR(I,1)
 688                 PATT(NATT,2)=PDR(I,2)
 689                 PATT(NATT,3)=PDR(I,3)
 690                 PATT(NATT,4)=PDR(I,4)
 691                 VATT(NATT,1)=V(I,1)
 692                 VATT(NATT,2)=V(I,2)
 693                 VATT(NATT,3)=V(I,3)
 694                 VATT(NATT,4)=V(I,4)
 695
 696                 EATT=EATT+PDR(I,4)
 697 450     CONTINUE
 698 C                       ********store the direct-produced particles
 699 C
 700         DENGY=EATT/(IHNT2(1)*HINT1(6)+IHNT2(3)*HINT1(7))-1.0
 701         IF(ABS(DENGY).GT.HIPR1(43).AND.IHPR2(20).NE.0
 702      &     .AND.IHPR2(21).EQ.0) THEN
 703         IF(IHPR2(10).NE.0) WRITE(6,*) 'Energy not conserved, repeat the
 704      &     event'
 705 C               call LULIST_HIJING(1)
 706                 GO TO 50
 707         ENDIF
 708
 709         RETURN
 710         END