ISAJET/isasusy/ssgwq2.F

   1 #include "isajet/pilot.h"
   2         REAL FUNCTION SSGWQ2(Q)
   3 C-----------------------------------------------------------------------
   4 C          SSGLBF: glss -> wiss + qk + qb
   5 C          The function phi of PRD36, 96 (1987); Eq. 3.2
   6 C-----------------------------------------------------------------------
   7 #if defined(CERNLIB_IMPNONE)
   8       IMPLICIT NONE
   9 #endif
  10 #include "isajet/sssm.inc"
  11 #include "isajet/sspar.inc"
  12 #include "isajet/sstmp.inc"
  13         REAL Q,PI
  14         DOUBLE PRECISION MZ,MG,MS,QS,MGS,MSS,MZS,FUN,TERM
  15         PI=4*ATAN(1.)
  16         MZ=TMP(1)
  17         MS=TMP(2)
  18         MG=AMGLSS
  19         QS=Q*Q
  20         MGS=MG*MG
  21         MZS=MZ*MZ
  22         MSS=MS*MS
  23         TERM=(MSS*MG-2*MSS*Q-MG*MZS)/(MG-2*Q)/(MSS-2*MG*Q-MZS)
  24         IF (TERM.LE.0.D0) THEN
  25           SSGWQ2=0.
  26           RETURN
  27         ELSE
  28         FUN=(-Q*(MGS-MZS-2*MG*Q)/(MGS-2*Q*MG)-(2*MG*Q-MSS+MZS)*
  29      $   DLOG(TERM)/2.D0/MG)/(MGS-MSS-2*MG*Q)
  30         SSGWQ2=PI**2*MG*MZ/2.*FUN
  31         RETURN
  32         END IF
  33         END