ISAJET/code/decva.F

   1 #include "isajet/pilot.h"
   2       LOGICAL FUNCTION DECVA(IP,NADD,IDABS,PREST)
   3 C
   4 C          Compute matrix element unpolarized for V-A.
   5 C          Auxiliary routine for DECAY.
   6 C
   7 C
   8 #if defined(CERNLIB_IMPNONE)
   9       IMPLICIT NONE
  10 #endif
  11 #include "isajet/itapes.inc"
  12 #include "isajet/wcon.inc"
  13 #include "isajet/partcl.inc"
  14 #include "isajet/dkytab.inc"
  15 #include "isajet/jetset.inc"
  16 #include "isajet/jwork.inc"
  17 #include "isajet/const.inc"
  18 #include "isajet/keys.inc"
  19 #include "isajet/pjets.inc"
  20 #include "isajet/xmssm.inc"
  21 #include "isajet/sspols.inc"
  22 C
  23       REAL PREST(4,6)
  24       REAL DOT,RANF,WT
  25       INTEGER IP,NADD,IDABS(5),I,K,I1,I2,IDIPA
  26 C
  27       DOT(I1,I2)=PREST(4,I1)*PREST(4,I2)-PREST(1,I1)*PREST(1,I2)
  28      $-PREST(2,I1)*PREST(2,I2)-PREST(3,I1)*PREST(3,I2)
  29 C
  30       IDIPA=IABS(IDENT(IP))
  31       IF(IDENT(NPTCL+1).LT.0) THEN
  32         WT=PPTCL(5,IP)*PREST(4,1)*DOT(2,3)
  33       ELSEIF(IDENT(NPTCL+2).LT.0) THEN
  34         WT=PPTCL(5,IP)*PREST(4,2)*DOT(1,3)
  35       ELSE
  36         WT=PPTCL(5,IP)*PREST(4,3)*DOT(1,2)
  37       ENDIF
  38       IF(WT.LT.RANF()*PPTCL(5,IP)**4/16.) THEN
  39         DECVA=.FALSE.
  40       ELSE
  41         DECVA=.TRUE.
  42       ENDIF
  43       RETURN
  44       END