hijing/src/hijcrs.f

0001 C
0002 C
0003 C
0004 C
0005         SUBROUTINE HIJCRS
0006 C       THIS IS TO CALCULATE THE CROSS SECTIONS OF JET PRODUCTION AND
0007 C       THE TOTAL INELASTIC CROSS SECTIONS.
0008         COMMON/HIPARNT/HIPR1(100),IHPR2(50),HINT1(100),IHNT2(50)
0009         SAVE  /HIPARNT/
0010         COMMON/NJET/N,IP_CRS
0011         SAVE  /NJET/
0012         EXTERNAL FHIN,FTOT,FNJET,FTOTJET,FTOTRIG
0013         IF(HINT1(1).GE.10.0) CALL CRSJET
0014 C                       ********calculate jet cross section(in mb)
0015 C
0016         APHX1=HIPR1(6)*(IHNT2(1)**0.3333333-1.0)
0017         APHX2=HIPR1(6)*(IHNT2(3)**0.3333333-1.0)
0018         HINT1(11)=HINT1(14)-APHX1*HINT1(15)
0019      &                  -APHX2*HINT1(16)+APHX1*APHX2*HINT1(17)
0020         HINT1(10)=GAUSS1(FTOTJET,0.0,20.0,0.01)
0021         HINT1(12)=GAUSS1(FHIN,0.0,20.0,0.01)
0022         HINT1(13)=GAUSS1(FTOT,0.0,20.0,0.01)
0023         HINT1(60)=HINT1(61)-APHX1*HINT1(62)
0024      &                  -APHX2*HINT1(63)+APHX1*APHX2*HINT1(64)
0025         HINT1(59)=GAUSS1(FTOTRIG,0.0,20.0,0.01)
0026         IF(HINT1(59).EQ.0.0) HINT1(59)=HINT1(60)
0027         IF(HINT1(1).GE.10.0) Then
0028            DO 20 I=0,20
0029               N=I
0030               HINT1(80+I)=GAUSS1(FNJET,0.0,20.0,0.01)/HINT1(12)
0031  20        CONTINUE
0032         ENDIF
0033         HINT1(10)=HINT1(10)*HIPR1(31)
0034         HINT1(12)=HINT1(12)*HIPR1(31)
0035         HINT1(13)=HINT1(13)*HIPR1(31)
0036         HINT1(59)=HINT1(59)*HIPR1(31)
0037 C               ********Total and Inel cross section are calculated
0038 C                       by Gaussian integration.
0039         IF(IHPR2(13).NE.0) THEN
0040         HIPR1(33)=1.36*(1.0+36.0/HINT1(1)**2)
0041      &             *ALOG(0.6+0.1*HINT1(1)**2)
0042         HIPR1(33)=HIPR1(33)/HINT1(12)
0043         ENDIF
0044 C               ********Parametrized cross section for single
0045 C                       diffractive reaction(Goulianos)
0046         RETURN
0047         END