ISAJET/isasusy/ssgwt4.F

   1 #include "isajet/pilot.h"
   2         REAL FUNCTION SSGWT4(E)
   3 C-----------------------------------------------------------------------
   4 C          SSGLBF: glss -> wiss + tp + bb
   5 C          Baer's FTBW12; EQ. A.3D OF BTW, MODIFIED FOR MB=/0
   6 C          Drees' G_4
   7 C-----------------------------------------------------------------------
   8 #if defined(CERNLIB_IMPNONE)
   9       IMPLICIT NONE
  10 #endif
  11 #include "isajet/sssm.inc"
  12 #include "isajet/sspar.inc"
  13 #include "isajet/sstmp.inc"
  14         REAL E
  15         DOUBLE PRECISION ET,MWI,MG,MT,MSB,MST,PT,EBMX
  16         DOUBLE PRECISION BOT,TOP,DFTBW,EBMN,XX
  17         DOUBLE PRECISION MB,Z,RDL,DEN,R1,R2,R3,SSDLAM,SN
  18 C
  19         ET=E
  20         MWI=TMP(1)
  21         MG=TMP(2)
  22         MT=TMP(3)
  23         MSB=TMP(4)
  24         MST=TMP(6)
  25         SN=TMP(8)
  26         MB=AMBT
  27 C
  28 C            Rewrite PT=DSQRT(ET**2-MT**2)
  29         PT=DSQRT((ET-MT)*(ET+MT))
  30         Z=(MG**2+MT**2-2*MG*ET+MB**2-MWI**2)/2.
  31         R1=1.D0+MT**2/MG**2-2.D0*ET/MG
  32         R2=MB**2/MG**2
  33         R3=MWI**2/MG**2
  34         RDL=DSQRT(DMAX1(0.D0,SSDLAM(R1,R2,R3)))
  35         DEN=MG**2+MT**2-2*ET*MG
  36         EBMX=(2*Z*(1.D0-ET/MG)+PT*MG*RDL)*MG/2.D0/DEN
  37         EBMN=(2*Z*(1.D0-ET/MG)-PT*MG*RDL)*MG/2.D0/DEN
  38         XX=(MSB**2+2*MG*EBMX-MG**2)/(MSB**2+2*MG*EBMN-MG**2)
  39         TOP=EBMX-EBMN-(MSB**2-2*MG*ET+MT**2-MWI**2)*DLOG(XX)/2.D0/MG
  40         BOT=(MG**2+MT**2-2*MG*ET-MST**2)
  41         DFTBW=-SN*MG*MWI*TOP/BOT
  42         SSGWT4=DFTBW
  43         RETURN
  44         END