HIJING/hijing1_36/fjetrig.F

   1 * $Id$
   2 C
   3 C
   4 C
   5         FUNCTION FJETRIG(X,WGT)
   6         IMPLICIT REAL*8(A-H,O-Z)
   7 #include "hiparnt.inc"
   8         DIMENSION X(10)
   9         SAVE
  10         PTMIN=ABS(HIPR1(10))-0.25
  11         PTMIN=MAX(PTMIN,DBLE(HIPR1(8)))
  12         AM2=0.D0
  13         IF(IHPR2(3).EQ.3) THEN
  14            AM2=HIPR1(7)**2
  15            PTMIN=MAX(0.0,HIPR1(10))
  16         ENDIF
  17         PTMAX=ABS(HIPR1(10))+0.25
  18         IF(HIPR1(10).LE.0.0) PTMAX=HINT1(1)/2.0-AM2
  19         IF(PTMAX.LE.PTMIN) PTMAX=PTMIN+0.25
  20         PT2=(PTMAX**2-PTMIN**2)*X(1)+PTMIN**2
  21         AMT2=PT2+AM2
  22         XT=2.0*DSQRT(AMT2)/HINT1(1)
  23         YMX1=DLOG(1.0/XT+DSQRT(1.0/XT**2-1.0))
  24         Y1=2.0*YMX1*X(2)-YMX1
  25         YMX2=DLOG(2.0/XT-DEXP(Y1))
  26         YMN2=DLOG(2.0/XT-DEXP(-Y1))
  27         Y2=(YMX2+YMN2)*X(3)-YMN2
  28         IF(IHPR2(3).EQ.3) THEN
  29            GTRIG=2.0*GHVQ(Y1,Y2,AMT2)
  30         ELSE IF(IHPR2(3).EQ.2) THEN
  31            GTRIG=2.0*GPHOTON(Y1,Y2,PT2)
  32         ELSE
  33            GTRIG=G(Y1,Y2,PT2)
  34         ENDIF
  35         FJETRIG=2.0*YMX1*(YMX2+YMN2)*(PTMAX**2-PTMIN**2)
  36      &          *GTRIG/2.0
  37         RETURN
  38         END