GEANT321/gheisha/pbanh.F

   1 *
   2 * $Id$
   3 *
   4 * $Log$
   5 * Revision 1.1.1.1  1995/10/24 10:20:58  cernlib
   6 * Geant
   7 *
   8 *
   9 #include "geant321/pilot.h"
  10 *CMZ :  3.21/02 29/03/94  15.41.38  by  S.Giani
  11 *-- Author :
  12       SUBROUTINE PBANH(NOPT)
  13 C *** ANTI PROTON ANNIHILATION AT REST ***
  14 C *** NVE 04-MAR-1988 CERN GENEVA ***
  15 C
  16 C ORIGIN : H.FESEFELDT (09-JULY-1987)
  17 C
  18 C NOPT=0    NO ANNIHILATION
  19 C NOPT=1    ANNIH.IN PI+ PI-
  20 C NOPT=2    ANNIH.IN PI0 PI0
  21 C NOPT=3    ANNIH.IN PI- PI0
  22 C NOPT=4    ANNIH.IN GAMMA GAMMA
  23 C
  24 #include "geant321/s_defcom.inc"
  25 C
  26       DIMENSION BRR(3)
  27       DIMENSION RNDM(3)
  28       DATA BRR/0.125,0.25,0.5/
  29 C
  30       PV(1,1)=0.
  31       PV(2,1)=0.
  32       PV(3,1)=0.
  33       PV(4,1)=ABS(RMASS(15))
  34       PV(5,1)=RMASS(15)
  35       PV(6,1)=-1.
  36       PV(7,1)=TOF
  37       PV(8,1)=IPART
  38       PV(9,1)=0.
  39       PV(10,1)=USERW
  40       IER(86)=IER(86)+1
  41       ISW=1
  42       CALL GRNDM(RNDM,1)
  43       RAN=RNDM(1)
  44       IF(RAN.GT.BRR(1)) ISW=2
  45       IF(RAN.GT.BRR(2)) ISW=3
  46       IF(RAN.GT.BRR(3)) ISW=4
  47       NOPT=ISW
  48 C**
  49 C**  EVAPORATION
  50 C**
  51       CALL COMPO
  52       IF (ISW .EQ. 1) THEN
  53          RMNVE1=RMASS(7)
  54          RMNVE2=RMASS(9)
  55       ELSEIF (ISW .EQ. 2) THEN
  56          RMNVE1=RMASS(8)
  57          RMNVE2=RMASS(8)
  58       ELSEIF (ISW .EQ. 3) THEN
  59          RMNVE1=RMASS(9)
  60          RMNVE2=RMASS(8)
  61       ELSEIF (ISW .EQ. 4) THEN
  62          RMNVE1=RMASS(1)
  63          RMNVE2=RMASS(1)
  64       ENDIF
  65       EK=RMASS(14)+ABS(RMASS(15))-RMNVE1-RMNVE2
  66       TKIN=EXNU(EK)
  67       EK=EK-TKIN
  68       IF(EK.LT.0.0001) EK=0.0001
  69       EK=0.5*EK
  70       EN=EK+0.5*(RMNVE1+RMNVE2)
  71       S=AMAS*AMAS+RMASS(14)**2+2.0*RMASS(14)*EN
  72       RS=SQRT(S)
  73       PCM=SQRT(ABS(EN*EN-RMNVE1*RMNVE2))
  74       CALL GRNDM(RNDM,2)
  75       PHI=2.*PI*RNDM(1)
  76       COST=-1.+2.*RNDM(2)
  77       SINT=SQRT(ABS((1.-COST)*(1.+COST)))
  78       PV(1,2)=PCM*SINT*COS(PHI)
  79       PV(2,2)=PCM*SINT*SIN(PHI)
  80       PV(3,2)=PCM*COST
  81       DO 1 I=1,3
  82     1 PV(I,3)=-PV(I,2)
  83       PV(5,2)=RMNVE1
  84       PV(5,3)=RMNVE2
  85       IF(ISW.LE.3) GOTO 2
  86       PV(5,2)=0.
  87       PV(5,3)=0.
  88     2 PV(4,2)=SQRT(PV(5,2)**2+PCM**2)
  89       PV(4,3)=SQRT(PV(5,3)**2+PCM**2)
  90       PV(7,2)=TOF
  91       PV(7,3)=TOF
  92       PV(9,2)=0.
  93       PV(9,3)=0.
  94       PV(10,2)=0.
  95       PV(10,3)=0.
  96       GOTO (21,22,23,24),ISW
  97    21 PV(6,2)=1.
  98       PV(6,3)=-1.
  99       PV(8,2)=7.
 100       PV(8,3)=9.
 101       GOTO 25
 102    22 PV(6,2)=0.
 103       PV(6,3)=0.
 104       PV(8,2)=8.
 105       PV(8,3)=8.
 106       GOTO 25
 107    23 PV(6,2)=-1.
 108       PV(6,3)=0.
 109       PV(8,2)=9.
 110       PV(8,3)=8.
 111       GOTO 25
 112    24 PV(6,2)=0.
 113       PV(6,3)=0.
 114       PV(8,2)=1.
 115       PV(8,3)=1.
 116    25 NT=3
 117       IF(ATNO2.LT.1.5) GOTO 40
 118       AFC=0.312+0.200*LOG(LOG(S))+S**1.5/6000.
 119 C     TARG=AFC*(ATNO2**0.33 -1.0)
 120       CFA=0.025*((ATNO2-1.)/120.)*EXP(-(ATNO2-1.)/120.)
 121       TARG=1.
 122       TEX=ENP(1)
 123       IF(TEX.LT.0.001) GOTO 445
 124       BLACK=(1.5+1.25*TARG)*ENP(1)/(ENP(1)+ENP(3))
 125       CALL POISSO(BLACK,NBL)
 126       IF(IFIX(TARG)+NBL.GT.ATNO2) NBL=ATNO2-TARG
 127       IF(NT+NBL.GT.MXGKPV-2) NBL=MXGKPV-2-NT
 128       IF(NBL.LE.0) GOTO 445
 129       EKIN=TEX/NBL
 130       EKIN2=0.
 131       CALL STEEP(XX)
 132       DO 441 I=1,NBL
 133       IF(NT.EQ.MXGKPV-2) GOTO 441
 134       IF(EKIN2.GT.TEX) GOTO 443
 135       CALL GRNDM(RNDM,1)
 136       RAN1=RNDM(1)
 137       CALL NORMAL(RAN2)
 138       EKIN1=-EKIN*LOG(RAN1)-CFA*(1.+0.5*RAN2)
 139       IF(EKIN1.LT.0.0) EKIN1=-0.010*LOG(RAN1)
 140       EKIN1=EKIN1*XX
 141       EKIN2=EKIN2+EKIN1
 142       IF(EKIN2.GT.TEX) EKIN1=TEX-(EKIN2-EKIN1)
 143       IF(EKIN1.LT.0.) EKIN1=0.001
 144       IPA1=16
 145       PNRAT=1.-ZNO2/ATNO2
 146       CALL GRNDM(RNDM,3)
 147       IF(RNDM(1).GT.PNRAT) IPA1=14
 148       NT=NT+1
 149       COST=-1.+RNDM(2)*2.
 150       SINT=SQRT(ABS(1.-COST*COST))
 151       PHI=TWPI*RNDM(3)
 152       IPA(NT)=-IPA1
 153       PV(5,NT)=ABS(RMASS(IPA1))
 154       PV(6,NT)=RCHARG(IPA1)
 155       PV(7,NT)=TOF
 156       PV(8,NT)=IPA1
 157       PV(9,NT)=0.
 158       PV(10,NT)=0.
 159       PV(4,NT)=EKIN1+PV(5,NT)
 160       PP=SQRT(ABS(PV(4,NT)**2-PV(5,NT)**2))
 161       PV(1,NT)=PP*SINT*SIN(PHI)
 162       PV(2,NT)=PP*SINT*COS(PHI)
 163       PV(3,NT)=PP*COST
 164   441 CONTINUE
 165   443 IF(ATNO2.LT.230.) GOTO 445
 166       IF(EK.GT.2.0) GOTO 445
 167       II=NT+1
 168       KK=0
 169       EKA=EK
 170       IF(EKA.GT.1.) EKA=EKA*EKA
 171       IF(EKA.LT.0.1) EKA=0.1
 172       IKA=IFIX(3.6/EKA)
 173       DO 444 I=1,NT
 174       II=II-1
 175       IF(IPA(II).NE.-14) GOTO 444
 176       IPA(II)=-16
 177       IPA1  = 16
 178       PV(5,II)=ABS(RMASS(IPA1))
 179       PV(6,II)=RCHARG(IPA1)
 180       PV(8,II)=IPA1
 181       KK=KK+1
 182       IF(KK.GT.IKA) GOTO 445
 183   444 CONTINUE
 184 C**
 185 C** THEN ALSO DEUTERONS, TRITONS AND ALPHAS
 186 C**
 187   445 TEX=ENP(3)
 188       IF(TEX.LT.0.001) GOTO 40
 189       BLACK=(1.5+1.25*TARG)*ENP(3)/(ENP(1)+ENP(3))
 190       CALL POISSO(BLACK,NBL)
 191       IF(NT+NBL.GT.MXGKPV-2) NBL=MXGKPV-2-NT
 192       IF(NBL.LE.0) GOTO 40
 193       EKIN=TEX/NBL
 194       EKIN2=0.
 195       CALL STEEP(XX)
 196       DO 442 I=1,NBL
 197       IF(NT.EQ.MXGKPV-2) GOTO 442
 198       IF(EKIN2.GT.TEX) GOTO 40
 199       CALL GRNDM(RNDM,1)
 200       RAN1=RNDM(1)
 201       CALL NORMAL(RAN2)
 202       EKIN1=-EKIN*LOG(RAN1)-CFA*(1.+0.5*RAN2)
 203       IF(EKIN1.LT.0.0) EKIN1=-0.010*LOG(RAN1)
 204       EKIN1=EKIN1*XX
 205       EKIN2=EKIN2+EKIN1
 206       IF(EKIN2.GT.TEX) EKIN1=TEX-(EKIN2-EKIN1)
 207       IF(EKIN1.LT.0.) EKIN1=0.001
 208       CALL GRNDM(RNDM,3)
 209       COST=-1.+RNDM(1)*2.
 210       SINT=SQRT(ABS(1.-COST*COST))
 211       PHI=TWPI*RNDM(2)
 212       RAN=RNDM(3)
 213       IPA(NT+1)=-30
 214       IF(RAN.GT.0.60) IPA(NT+1)=-31
 215       IF(RAN.GT.0.90) IPA(NT+1)=-32
 216       INVE=ABS(IPA(NT+1))
 217       PV(5,NT+1)=RMASS(INVE)
 218       NT=NT+1
 219       PV(6,NT)=RCHARG(INVE)
 220       PV(7,NT)=TOF
 221       PV(8,NT)=ABS(IPA(NT))
 222       PV(9,NT)=0.
 223       PV(10,NT)=0.
 224       PV(4,NT)=PV(5,NT)+EKIN1
 225       PP=SQRT(ABS(PV(4,NT)**2-PV(5,NT)**2))
 226       PV(1,NT)=PP*SINT*SIN(PHI)
 227       PV(2,NT)=PP*SINT*COS(PHI)
 228       PV(3,NT)=PP*COST
 229   442 CONTINUE
 230    40 INTCT=INTCT+1.
 231       CALL SETCUR(2)
 232       NTK=NTK+1
 233       IF(NT.EQ.2) GO TO 9999
 234       DO 50 I=3,NT
 235       IF(NTOT.LT.NSIZE/12) GOTO 43
 236       GO TO 9999
 237    43 CALL SETTRK(I)
 238    50 CONTINUE
 239       CALL LENGTX(3,PP)
 240       IF(NPRT(3))
 241      *WRITE(NEWBCD,1001) XEND,YEND,ZEND,P,NCH,PP,PV(6,3)
 242 1001  FORMAT(1H0,'PB ANNIHILATION AT REST  POSITION',3(1X,F8.2),1X,
 243      * 'PI MOMENTA,CHARGES',2(1X,F8.4,1X,F4.1))
 244 C
 245  9999 CONTINUE
 246       END