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 #include "hiparnt.inc"
 159 C
 160 #include "hijcrdn.inc"
 161 #include "himain1.inc"
 162 #include "himain2.inc"
 163 #include "histrng.inc"
 164 #include "hijjet1.inc"
 165 #include "hijjet2.inc"
 166 #include "hijjet4.inc"
 167 C
 168 #include "lujets_hijing.inc"
 169 #include "ludat1_hijing.inc"
 170         SAVE
 171
 172         BMAX=MIN(BMAX0,HIPR1(34)+HIPR1(35))
 173         BMIN=MIN(BMIN0,BMAX)
 174         IF(IHNT2(1).LE.1 .AND. IHNT2(3).LE.1) THEN
 175                 BMIN=0.0
 176                 BMAX=2.5*SQRT(HIPR1(31)*0.1/HIPR1(40))
 177         ENDIF
 178 C                       ********HIPR1(31) is in mb =0.1fm**2
 179 C*******THE FOLLOWING IS TO SELECT THE COORDINATIONS OF NUCLEONS
 180 C       BOTH IN PROJECTILE AND TARGET NUCLEAR( in fm)
 181 C
 182         YP(1,1)=0.0
 183         YP(2,1)=0.0
 184         YP(3,1)=0.0
 185         IF(IHNT2(1).LE.1) GO TO 14
 186         DO 10 KP=1,IHNT2(1)
 187 5       R=HIRND(1)
 188         X=RLU_HIJING(0)
 189         CX=2.0*X-1.0
 190         SX=SQRT(1.0-CX*CX)
 191 C               ********choose theta from uniform cos(theta) distr
 192         PHI=RLU_HIJING(0)*2.0*HIPR1(40)
 193 C               ********choose phi form uniform phi distr 0 to 2*pi
 194         YP(1,KP)=R*SX*COS(PHI)
 195         YP(2,KP)=R*SX*SIN(PHI)
 196         YP(3,KP)=R*CX
 197         IF(HIPR1(29).EQ.0.0) GO TO 10
 198         DO 8  KP2=1,KP-1
 199                 DNBP1=(YP(1,KP)-YP(1,KP2))**2
 200                 DNBP2=(YP(2,KP)-YP(2,KP2))**2
 201                 DNBP3=(YP(3,KP)-YP(3,KP2))**2
 202                 DNBP=DNBP1+DNBP2+DNBP3
 203                 IF(DNBP.LT.HIPR1(29)*HIPR1(29)) GO TO 5
 204 C                       ********two neighbors cannot be closer than
 205 C                               HIPR1(29)
 206 8       CONTINUE
 207 10      CONTINUE
 208         DO 12 I=1,IHNT2(1)-1
 209         DO 12 J=I+1,IHNT2(1)
 210         IF(YP(3,I).GT.YP(3,J)) GO TO 12
 211         Y1=YP(1,I)
 212         Y2=YP(2,I)
 213         Y3=YP(3,I)
 214         YP(1,I)=YP(1,J)
 215         YP(2,I)=YP(2,J)
 216         YP(3,I)=YP(3,J)
 217         YP(1,J)=Y1
 218         YP(2,J)=Y2
 219         YP(3,J)=Y3
 220 12      CONTINUE
 221 C
 222 C******************************
 223 14      YT(1,1)=0.0
 224         YT(2,1)=0.0
 225         YT(3,1)=0.0
 226         IF(IHNT2(3).LE.1) GO TO 24
 227         DO 20 KT=1,IHNT2(3)
 228 15      R=HIRND(2)
 229         X=RLU_HIJING(0)
 230         CX=2.0*X-1.0
 231         SX=SQRT(1.0-CX*CX)
 232 C               ********choose theta from uniform cos(theta) distr
 233         PHI=RLU_HIJING(0)*2.0*HIPR1(40)
 234 C               ********chose phi form uniform phi distr 0 to 2*pi
 235         YT(1,KT)=R*SX*COS(PHI)
 236         YT(2,KT)=R*SX*SIN(PHI)
 237         YT(3,KT)=R*CX
 238         IF(HIPR1(29).EQ.0.0) GO TO 20
 239         DO 18  KT2=1,KT-1
 240                 DNBT1=(YT(1,KT)-YT(1,KT2))**2
 241                 DNBT2=(YT(2,KT)-YT(2,KT2))**2
 242                 DNBT3=(YT(3,KT)-YT(3,KT2))**2
 243                 DNBT=DNBT1+DNBT2+DNBT3
 244                 IF(DNBT.LT.HIPR1(29)*HIPR1(29)) GO TO 15
 245 C                       ********two neighbors cannot be closer than
 246 C                               HIPR1(29)
 247 18      CONTINUE
 248 20      CONTINUE
 249         DO 22 I=1,IHNT2(3)-1
 250         DO 22 J=I+1,IHNT2(3)
 251         IF(YT(3,I).LT.YT(3,J)) GO TO 22
 252         Y1=YT(1,I)
 253         Y2=YT(2,I)
 254         Y3=YT(3,I)
 255         YT(1,I)=YT(1,J)
 256         YT(2,I)=YT(2,J)
 257         YT(3,I)=YT(3,J)
 258         YT(1,J)=Y1
 259         YT(2,J)=Y2
 260         YT(3,J)=Y3
 261 22      CONTINUE
 262
 263 C********************
 264 24      MISS=-1
 265
 266 50      MISS=MISS+1
 267         IF(MISS.GT.50) THEN
 268            WRITE(6,*) 'infinite loop happened in  HIJING'
 269            STOP
 270         ENDIF
 271
 272         NATT=0
 273         JATT=0
 274         EATT=0.0
 275         CALL HIJINI
 276         NLOP=0
 277 C                       ********Initialize for a new event
 278 60      NT=0
 279         NP=0
 280         N0=0
 281         N01=0
 282         N10=0
 283         N11=0
 284         NSG=0
 285         NCOLT=0
 286
 287 C****   BB IS THE ABSOLUTE VALUE OF IMPACT PARAMETER,BB**2 IS
 288 C       RANDOMLY GENERATED AND ITS ORIENTATION IS RANDOMLY SET
 289 C       BY THE ANGLE PHI  FOR EACH COLLISION.******************
 290 C
 291         BB=SQRT(BMIN**2+RLU_HIJING(0)*(BMAX**2-BMIN**2))
 292         PHI=2.0*HIPR1(40)*RLU_HIJING(0)
 293         BBX=BB*COS(PHI)
 294         BBY=BB*SIN(PHI)
 295         HINT1(19)=BB
 296         HINT1(20)=PHI
 297 C
 298         DO 70 JP=1,IHNT2(1)
 299         DO 70 JT=1,IHNT2(3)
 300            SCIP(JP,JT)=-1.0
 301            B2=(YP(1,JP)+BBX-YT(1,JT))**2+(YP(2,JP)+BBY-YT(2,JT))**2
 302            R2=B2*HIPR1(40)/HIPR1(31)/0.1
 303 C               ********mb=0.1*fm, YP is in fm,HIPR1(31) is in mb
 304            RRB1=MIN((YP(1,JP)**2+YP(2,JP)**2)
 305      &          /1.2**2/REAL(IHNT2(1))**0.6666667,1.0)
 306            RRB2=MIN((YT(1,JT)**2+YT(2,JT)**2)
 307      &          /1.2**2/REAL(IHNT2(3))**0.6666667,1.0)
 308            APHX1=HIPR1(6)*4.0/3.0*(IHNT2(1)**0.3333333-1.0)
 309      &           *SQRT(1.0-RRB1)
 310            APHX2=HIPR1(6)*4.0/3.0*(IHNT2(3)**0.3333333-1.0)
 311      &           *SQRT(1.0-RRB2)
 312            HINT1(18)=HINT1(14)-APHX1*HINT1(15)
 313      &                  -APHX2*HINT1(16)+APHX1*APHX2*HINT1(17)
 314            IF(IHPR2(14).EQ.0.OR.
 315      &          (IHNT2(1).EQ.1.AND.IHNT2(3).EQ.1)) THEN
 316               GS=1.0-EXP(-(HIPR1(30)+HINT1(18))*ROMG(R2)/HIPR1(31))
 317               RANTOT=RLU_HIJING(0)
 318               IF(RANTOT.GT.GS) GO TO 70
 319               GO TO 65
 320            ENDIF
 321            GSTOT_0=2.0*(1.0-EXP(-(HIPR1(30)+HINT1(18))
 322      &             /HIPR1(31)/2.0*ROMG(0.0)))
 323            R2=R2/GSTOT_0
 324            GS=1.0-EXP(-(HIPR1(30)+HINT1(18))/HIPR1(31)*ROMG(R2))
 325            GSTOT=2.0*(1.0-SQRT(1.0-GS))
 326            RANTOT=RLU_HIJING(0)*GSTOT_0
 327            IF(RANTOT.GT.GSTOT) GO TO 70
 328            IF(RANTOT.GT.GS) THEN
 329               CALL HIJCSC(JP,JT)
 330               GO TO 70
 331 C                       ********perform elastic collisions
 332            ENDIF
 333  65        SCIP(JP,JT)=R2
 334            RNIP(JP,JT)=RANTOT
 335            SJIP(JP,JT)=HINT1(18)
 336            NCOLT=NCOLT+1
 337            IPCOL(NCOLT)=JP
 338            ITCOL(NCOLT)=JT
 339 70      CONTINUE
 340 C               ********total number interactions proj and targ has
 341 C                               suffered
 342         IF(NCOLT.EQ.0) THEN
 343            NLOP=NLOP+1
 344            IF(NLOP.LE.20.OR.
 345      &           (IHNT2(1).EQ.1.AND.IHNT2(3).EQ.1)) GO TO 60
 346            RETURN
 347         ENDIF
 348 C               ********At large impact parameter, there maybe no
 349 C                       interaction at all. For NN collision
 350 C                       repeat the event until interaction happens
 351 C
 352         IF(IHPR2(3).NE.0) THEN
 353            NHARD=1+INT(RLU_HIJING(0)*(NCOLT-1)+0.5)
 354            NHARD=MIN(NHARD,NCOLT)
 355            JPHARD=IPCOL(NHARD)
 356            JTHARD=ITCOL(NHARD)
 357         ENDIF
 358 C
 359         IF(IHPR2(9).EQ.1) THEN
 360                 NMINI=1+INT(RLU_HIJING(0)*(NCOLT-1)+0.5)
 361                 NMINI=MIN(NMINI,NCOLT)
 362                 JPMINI=IPCOL(NMINI)
 363                 JTMINI=ITCOL(NMINI)
 364         ENDIF
 365 C               ********Specifying the location of the hard and
 366 C                       minijet if they are enforced by user
 367 C
 368         DO 200 JP=1,IHNT2(1)
 369         DO 200 JT=1,IHNT2(3)
 370         IF(SCIP(JP,JT).EQ.-1.0) GO TO 200
 371                 NFP(JP,11)=NFP(JP,11)+1
 372                 NFT(JT,11)=NFT(JT,11)+1
 373         IF(NFP(JP,5).LE.1 .AND. NFT(JT,5).GT.1) THEN
 374                 NP=NP+1
 375                 N01=N01+1
 376         ELSE IF(NFP(JP,5).GT.1 .AND. NFT(JT,5).LE.1) THEN
 377                 NT=NT+1
 378                 N10=N10+1
 379         ELSE IF(NFP(JP,5).LE.1 .AND. NFT(JT,5).LE.1) THEN
 380                 NP=NP+1
 381                 NT=NT+1
 382                 N0=N0+1
 383         ELSE IF(NFP(JP,5).GT.1 .AND. NFT(JT,5).GT.1) THEN
 384                 N11=N11+1
 385         ENDIF
 386         JOUT=0
 387         NFP(JP,10)=0
 388         NFT(JT,10)=0
 389 C*****************************************************************
 390         IF(IHPR2(8).EQ.0 .AND. IHPR2(3).EQ.0) GO TO 160
 391 C               ********When IHPR2(8)=0 no jets are produced
 392         IF(NFP(JP,6).LT.0 .OR. NFT(JT,6).LT.0) GO TO 160
 393 C               ********jets can not be produced for (JP,JT)
 394 C                       because not enough energy avaible for
 395 C                               JP or JT
 396         R2=SCIP(JP,JT)
 397         HINT1(18)=SJIP(JP,JT)
 398         TT=ROMG(R2)*HINT1(18)/HIPR1(31)
 399         TTS=HIPR1(30)*ROMG(R2)/HIPR1(31)
 400         NJET=0
 401         IF(IHPR2(3).NE.0 .AND. JP.EQ.JPHARD .AND. JT.EQ.JTHARD) THEN
 402            CALL JETINI(JP,JT,1)
 403            CALL HIJHRD(JP,JT,0,JFLG,0)
 404            HINT1(26)=HINT1(47)
 405            HINT1(27)=HINT1(48)
 406            HINT1(28)=HINT1(49)
 407            HINT1(29)=HINT1(50)
 408            HINT1(36)=HINT1(67)
 409            HINT1(37)=HINT1(68)
 410            HINT1(38)=HINT1(69)
 411            HINT1(39)=HINT1(70)
 412 C
 413            IF(ABS(HINT1(46)).GT.HIPR1(11).AND.JFLG.EQ.2) NFP(JP,7)=1
 414            IF(ABS(HINT1(56)).GT.HIPR1(11).AND.JFLG.EQ.2) NFT(JT,7)=1
 415            IF(MAX(ABS(HINT1(46)),ABS(HINT1(56))).GT.HIPR1(11).AND.
 416      &                          JFLG.GE.3) IASG(NSG,3)=1
 417            IHNT2(9)=IHNT2(14)
 418            IHNT2(10)=IHNT2(15)
 419            DO 105 I05=1,5
 420               HINT1(20+I05)=HINT1(40+I05)
 421               HINT1(30+I05)=HINT1(50+I05)
 422  105       CONTINUE
 423            JOUT=1
 424            IF(IHPR2(8).EQ.0) GO TO 160
 425            RRB1=MIN((YP(1,JP)**2+YP(2,JP)**2)/1.2**2
 426      &          /REAL(IHNT2(1))**0.6666667,1.0)
 427            RRB2=MIN((YT(1,JT)**2+YT(2,JT)**2)/1.2**2
 428      &          /REAL(IHNT2(3))**0.6666667,1.0)
 429            APHX1=HIPR1(6)*4.0/3.0*(IHNT2(1)**0.3333333-1.0)
 430      &           *SQRT(1.0-RRB1)
 431            APHX2=HIPR1(6)*4.0/3.0*(IHNT2(3)**0.3333333-1.0)
 432      &           *SQRT(1.0-RRB2)
 433            HINT1(65)=HINT1(61)-APHX1*HINT1(62)
 434      &                  -APHX2*HINT1(63)+APHX1*APHX2*HINT1(64)
 435            TTRIG=ROMG(R2)*HINT1(65)/HIPR1(31)
 436            NJET=-1
 437 C               ********subtract the trigger jet from total number
 438 C                       of jet production  to be done since it has
 439 C                               already been produced here
 440            XR1=-ALOG(EXP(-TTRIG)+RLU_HIJING(0)*(1.0-EXP(-TTRIG)))
 441  106       NJET=NJET+1
 442            XR1=XR1-ALOG(RLU_HIJING(0))
 443            IF(XR1.LT.TTRIG) GO TO 106
 444            XR=0.0
 445  107       NJET=NJET+1
 446            XR=XR-ALOG(RLU_HIJING(0))
 447            IF(XR.LT.TT-TTRIG) GO TO 107
 448            NJET=NJET-1
 449            GO TO 112
 450         ENDIF
 451 C               ********create a hard interaction with specified P_T
 452 c                                when IHPR2(3)>0
 453         IF(IHPR2(9).EQ.1.AND.JP.EQ.JPMINI.AND.JT.EQ.JTMINI) GO TO 110
 454 C               ********create at least one pair of mini jets
 455 C                       when IHPR2(9)=1
 456 C
 457         IF(IHPR2(8).GT.0 .AND.RNIP(JP,JT).LT.EXP(-TT)*
 458      &          (1.0-EXP(-TTS))) GO TO 160
 459 C               ********this is the probability for no jet production
 460 110     XR=-ALOG(EXP(-TT)+RLU_HIJING(0)*(1.0-EXP(-TT)))
 461 111     NJET=NJET+1
 462         XR=XR-ALOG(RLU_HIJING(0))
 463         IF(XR.LT.TT) GO TO 111
 464 112     NJET=MIN(NJET,IHPR2(8))
 465         IF(IHPR2(8).LT.0)  NJET=ABS(IHPR2(8))
 466 C               ******** Determine number of mini jet production
 467 C
 468         DO 150 I_JET=1,NJET
 469            CALL JETINI(JP,JT,0)
 470            CALL HIJHRD(JP,JT,JOUT,JFLG,1)
 471 C               ********JFLG=1 jets valence quarks, JFLG=2 with
 472 C                       gluon jet, JFLG=3 with q-qbar prod for
 473 C                       (JP,JT). If JFLG=0 jets can not be produced
 474 C                       this time. If JFLG=-1, error occured abandon
 475 C                       this event. JOUT is the total hard scat for
 476 C                       (JP,JT) up to now.
 477            IF(JFLG.EQ.0) GO TO 160
 478            IF(JFLG.LT.0) THEN
 479               IF(IHPR2(10).NE.0) WRITE(6,*) 'error occured in HIJHRD'
 480               GO TO 50
 481            ENDIF
 482            JOUT=JOUT+1
 483            IF(ABS(HINT1(46)).GT.HIPR1(11).AND.JFLG.EQ.2) NFP(JP,7)=1
 484            IF(ABS(HINT1(56)).GT.HIPR1(11).AND.JFLG.EQ.2) NFT(JT,7)=1
 485            IF(MAX(ABS(HINT1(46)),ABS(HINT1(56))).GT.HIPR1(11).AND.
 486      &                  JFLG.GE.3) IASG(NSG,3)=1
 487 C               ******** jet with PT>HIPR1(11) will be quenched
 488  150    CONTINUE
 489  160    CONTINUE
 490         CALL HIJSFT(JP,JT,JOUT,IERROR)
 491         IF(IERROR.NE.0) THEN
 492            IF(IHPR2(10).NE.0) WRITE(6,*) 'error occured in HIJSFT'
 493            GO TO 50
 494         ENDIF
 495 C
 496 C               ********conduct soft scattering between JP and JT
 497         JATT=JATT+JOUT
 498
 499 200     CONTINUE
 500
 501 C********perform jet quenching for jets with PT>HIPR1(11)**********
 502
 503         IF((IHPR2(8).NE.0.OR.IHPR2(3).NE.0).AND.IHPR2(4).GT.0.AND.
 504      &                  IHNT2(1).GT.1.AND.IHNT2(3).GT.1) THEN
 505                 DO 271 I=1,IHNT2(1)
 506                         IF(NFP(I,7).EQ.1) CALL QUENCH(I,1)
 507 271             CONTINUE
 508                 DO 272 I=1,IHNT2(3)
 509                         IF(NFT(I,7).EQ.1) CALL QUENCH(I,2)
 510 272             CONTINUE
 511                 DO 273 ISG=1,NSG
 512                         IF(IASG(ISG,3).EQ.1) CALL QUENCH(ISG,3)
 513 273             CONTINUE
 514         ENDIF
 515 C
 516 C**************fragment all the string systems in the following*****
 517 C
 518 C********N_ST is where particle information starts
 519 C********N_STR+1 is the number of strings in fragmentation
 520 C********the number of strings before a line is stored in K(I,4)
 521 C********IDSTR is id number of the string system (91,92 or 93)
 522 C
 523         IF(IHPR2(20).NE.0) THEN
 524            DO 360 ISG=1,NSG
 525                 CALL HIJFRG(ISG,3,IERROR)
 526                 IF(MSTU(24).NE.0 .OR.IERROR.GT.0) THEN
 527                    MSTU(24)=0
 528                    MSTU(28)=0
 529                    IF(IHPR2(10).NE.0) THEN
 530                       call LULIST_HIJING(1)
 531                       WRITE(6,*) 'error occured, repeat the event'
 532                    ENDIF
 533                    GO TO 50
 534                 ENDIF
 535 C                       ********Check errors
 536 C
 537                 N_ST=1
 538                 IDSTR=92
 539                 IF(IHPR2(21).EQ.0) THEN
 540                    CALL LUEDIT_HIJING(2)
 541                 ELSE
 542 351                N_ST=N_ST+1
 543                    IF(K(N_ST,2).LT.91.OR.K(N_ST,2).GT.93) GO TO  351
 544                    IDSTR=K(N_ST,2)
 545                    N_ST=N_ST+1
 546                 ENDIF
 547 C
 548                 IF(FRAME.EQ.'LAB') THEN
 549                         CALL HIBOOST
 550                 ENDIF
 551 C               ******** boost back to lab frame(if it was in)
 552 C
 553                 N_STR=0
 554                 DO 360 I=N_ST,N
 555                    IF(K(I,2).EQ.IDSTR) THEN
 556                       N_STR=N_STR+1
 557                       GO TO 360
 558                    ENDIF
 559                    K(I,4)=N_STR
 560                    NATT=NATT+1
 561                    KATT(NATT,1)=K(I,2)
 562                    KATT(NATT,2)=20
 563                    KATT(NATT,4)=K(I,1)
 564                    IF(K(I,3).EQ.0 .OR. K(K(I,3),2).EQ.IDSTR) THEN
 565                       KATT(NATT,3)=0
 566                    ELSE
 567                       KATT(NATT,3)=NATT-I+K(I,3)+N_STR-K(K(I,3),4)
 568                    ENDIF
 569 C       ****** identify the mother particle
 570                    PATT(NATT,1)=P(I,1)
 571                    PATT(NATT,2)=P(I,2)
 572                    PATT(NATT,3)=P(I,3)
 573                    PATT(NATT,4)=P(I,4)
 574                    EATT=EATT+P(I,4)
 575 360        CONTINUE
 576 C               ********Fragment the q-qbar jets systems *****
 577 C
 578            JTP(1)=IHNT2(1)
 579            JTP(2)=IHNT2(3)
 580            DO 400 NTP=1,2
 581            DO 400 J_JTP=1,JTP(NTP)
 582                 CALL HIJFRG(J_JTP,NTP,IERROR)
 583                 IF(MSTU(24).NE.0 .OR. IERROR.GT.0) THEN
 584                    MSTU(24)=0
 585                    MSTU(28)=0
 586                    IF(IHPR2(10).NE.0) THEN
 587                       call LULIST_HIJING(1)
 588                       WRITE(6,*) 'error occured, repeat the event'
 589                    ENDIF
 590                    GO TO 50
 591                 ENDIF
 592 C                       ********check errors
 593 C
 594                 N_ST=1
 595                 IDSTR=92
 596                 IF(IHPR2(21).EQ.0) THEN
 597                    CALL LUEDIT_HIJING(2)
 598                 ELSE
 599 381                N_ST=N_ST+1
 600                    IF(K(N_ST,2).LT.91.OR.K(N_ST,2).GT.93) GO TO  381
 601                    IDSTR=K(N_ST,2)
 602                    N_ST=N_ST+1
 603                 ENDIF
 604                 IF(FRAME.EQ.'LAB') THEN
 605                         CALL HIBOOST
 606                 ENDIF
 607 C               ******** boost back to lab frame(if it was in)
 608 C
 609                 NFTP=NFP(J_JTP,5)
 610                 IF(NTP.EQ.2) NFTP=10+NFT(J_JTP,5)
 611                 N_STR=0
 612                 DO 390 I=N_ST,N
 613                    IF(K(I,2).EQ.IDSTR) THEN
 614                       N_STR=N_STR+1
 615                       GO TO 390
 616                    ENDIF
 617                    K(I,4)=N_STR
 618                    NATT=NATT+1
 619                    KATT(NATT,1)=K(I,2)
 620                    KATT(NATT,2)=NFTP
 621                    KATT(NATT,4)=K(I,1)
 622                    IF(K(I,3).EQ.0 .OR. K(K(I,3),2).EQ.IDSTR) THEN
 623                       KATT(NATT,3)=0
 624                    ELSE
 625                       KATT(NATT,3)=NATT-I+K(I,3)+N_STR-K(K(I,3),4)
 626                    ENDIF
 627 C       ****** identify the mother particle
 628                    PATT(NATT,1)=P(I,1)
 629                    PATT(NATT,2)=P(I,2)
 630                    PATT(NATT,3)=P(I,3)
 631                    PATT(NATT,4)=P(I,4)
 632                    EATT=EATT+P(I,4)
 633 390             CONTINUE
 634 400        CONTINUE
 635 C               ********Fragment the q-qq related string systems
 636         ENDIF
 637
 638         DO 450 I=1,NDR
 639                 NATT=NATT+1
 640                 KATT(NATT,1)=KFDR(I)
 641                 KATT(NATT,2)=40
 642                 KATT(NATT,3)=0
 643                 PATT(NATT,1)=PDR(I,1)
 644                 PATT(NATT,2)=PDR(I,2)
 645                 PATT(NATT,3)=PDR(I,3)
 646                 PATT(NATT,4)=PDR(I,4)
 647                 EATT=EATT+PDR(I,4)
 648 450     CONTINUE
 649 C                       ********store the direct-produced particles
 650 C
 651         DENGY=EATT/(IHNT2(1)*HINT1(6)+IHNT2(3)*HINT1(7))-1.0
 652         IF(ABS(DENGY).GT.HIPR1(43).AND.IHPR2(20).NE.0
 653      &     .AND.IHPR2(21).EQ.0) THEN
 654         IF(IHPR2(10).NE.0) WRITE(6,*) 'Energy not conserved, repeat the
 655      &     event'
 656 C               call LULIST_HIJING(1)
 657                 GO TO 50
 658         ENDIF
 659         RETURN
 660         END