GEANT321/fluka/energi.F

   1 *
   2 * $Id$
   3 *
   4 * $Log$
   5 * Revision 1.1.1.1  1995/10/24 10:20:00  cernlib
   6 * Geant
   7 *
   8 *
   9 #include "geant321/pilot.h"
  10 *CMZ :  3.21/02 29/03/94  15.41.44  by  S.Giani
  11 *-- Author :
  12 *$ CREATE ENERGI.FOR
  13 *COPY ENERGI
  14 *
  15 *=== energi ===========================================================*
  16 *
  17       SUBROUTINE ENERGI(IT,LL,LT,IV,RE,HMA,HE,E0,A1)
  18
  19 #include "geant321/dblprc.inc"
  20 #include "geant321/dimpar.inc"
  21 #include "geant321/iounit.inc"
  22 *
  23 *----------------------------------------------------------------------*
  24 *  Energi89: slight revision by A. Ferrari                             *
  25 *----------------------------------------------------------------------*
  26 *
  27 *      INCLUDE '(BAMJCM)'
  28 #include "geant321/finpar2.inc"
  29       DIMENSION IV(*),RE(*)
  30       REAL RNDM(1)
  31 C     SAMPLES THE ENERGY OF THE CREATED HADRON
  32 C*****HE IS THE ENERGY OF THE ACTUAL HADRON
  33       I=IT
  34       J=IT-1
  35       HMA=AMF(I)
  36       IF(IT .EQ. 1) RX=E0
  37       IF(IT .GT. 1) RX=RE(J)
  38       CALL GRNDM(RNDM,1)
  39       X   = RNDM(1)
  40       IVY = IV(I)
  41       GO TO (1,2,2,1,1,1,2,2,1,1),IVY
  42 C     MESON VERTEX
  43     1 AX=(1.D0-A1)/(3.D0*A1)
  44       C=1.D0/((1.D0-A1)*(1.D0-HMA/RX)+3.D0*.5D0*A1*(1.D0-HMA/RX)**2)
  45       ETA=-AX+SQRT(AX**2+X*2.D0/(3.D0*A1*C))
  46       GO TO 3
  47 C     BARYON VERTEX
  48     2 CY=1.D0/((1.D0-A1)*(1.D0-HMA/RX)+A1*(1.D0-HMA/RX)**3)
  49       BY=X/(2.D0*A1*CY)
  50       BZ=((1.D0-A1)/(3.D0*A1))**3
  51       BV=BY+SQRT(BY**2+BZ)
  52       BU=BY-SQRT(BY**2+BZ)
  53       IF(BU.LT.0.D0) BU1=ABS(BU)
  54       BU3=BU1**(1.D0/3.D0)
  55       BV3=BV**(1.D0/3.D0)
  56       IF(BU.LT.0.D0) BU3=-BU3
  57       ETA=BU3+BV3
  58       GO TO 3
  59     3 CONTINUE
  60       RE(I)=ETA*RX
  61       HE=(1.D0-ETA)*RX
  62       HEF(I)=HE
  63       RETURN
  64       END