ISAJET/isasusy/ssgx2.F

   1 #include "isajet/pilot.h"
   2         REAL FUNCTION SSGX2(ET)
   3 C-----------------------------------------------------------------------
   4 C          SSGLBF: glss -> ziss + tp + tb
   5 C          Baer's XT2 - PHI- eq. a.6.b of prd45,142 (1992)
   6 C          Modified for t_1 and t_2 eigenstates
   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 ET
  15         DOUBLE PRECISION DET,DMG,DMT,DMZ,DMT1,DMT2,TOP,BOT,DXT2
  16         DOUBLE PRECISION XT,MUT,MUZ,XMIN,XMAX,EMIN,EMAX,SSDLAM,PI
  17         DATA PI/3.14159265D0/
  18         DET=ET
  19         DMG=TMP(1)
  20         DMT=TMP(2)
  21         DMZ=TMP(3)
  22         DMT1=TMP(4)
  23         DMT2=TMP(5)
  24         XT=2*DET/DMG
  25         MUT=(DMT/DMG)**2
  26         MUZ=(DMZ/DMG)**2
  27         XMIN=((2.D0-XT)*(1.D0+2*MUT-MUZ-XT)-DSQRT(DMAX1(0.D0,
  28      $   (XT**2-4*MUT)*SSDLAM((1.D0+MUT-XT),MUT,MUZ))))
  29      $   /2.D0/(1.D0-XT+MUT)
  30         XMAX=((2.D0-XT)*(1.D0+2*MUT-MUZ-XT)+DSQRT(DMAX1(0.D0,
  31      $   (XT**2-4*MUT)*SSDLAM((1.D0+MUT-XT),MUT,MUZ))))
  32      $   /2.D0/(1.D0-XT+MUT)
  33         EMIN=XMIN*DMG/2.D0
  34         EMAX=XMAX*DMG/2.D0
  35         TOP=DMG**2-2*DMG*EMAX+DMT**2-DMT2**2
  36         BOT=DMG**2-2*DMG*EMIN+DMT**2-DMT2**2
  37         DXT2=(-(EMAX-EMIN)-(2*DET*DMG+DMZ**2-DMT**2-DMT2**2)/2.D0/DMG*
  38      $      DLOG(TOP/BOT))*PI**2/2.D0*DMG*DMZ/
  39      $      (DMG**2+DMT**2-DMT1**2-2*DMG*DET)
  40         SSGX2=DXT2
  41         RETURN
  42         END