pythiaeRHIC/pythia/upveto.f

0001
0002 C...Old example: handles a simple Pythia 6.4 event file.
0003
0004 c      SUBROUTINE UPEVNT
0005
0006 C...Double precision and integer declarations.
0007 c      IMPLICIT DOUBLE PRECISION(A-H, O-Z)
0008 c      IMPLICIT INTEGER(I-N)
0009
0010 C...Commonblocks.
0011 c      COMMON/PYDAT1/MSTU(200),PARU(200),MSTJ(200),PARJ(200)
0012 c      COMMON/PYPARS/MSTP(200),PARP(200),MSTI(200),PARI(200)
0013 c      SAVE /PYDAT1/,/PYPARS/
0014
0015 C...User process event common block.
0016 c      INTEGER MAXNUP
0017 c      PARAMETER (MAXNUP=500)
0018 c      INTEGER NUP,IDPRUP,IDUP,ISTUP,MOTHUP,ICOLUP
0019 c      DOUBLE PRECISION XWGTUP,SCALUP,AQEDUP,AQCDUP,PUP,VTIMUP,SPINUP
0020 c      COMMON/HEPEUP/NUP,IDPRUP,XWGTUP,SCALUP,AQEDUP,AQCDUP,IDUP(MAXNUP),
0021 c     &ISTUP(MAXNUP),MOTHUP(2,MAXNUP),ICOLUP(2,MAXNUP),PUP(5,MAXNUP),
0022 c     &VTIMUP(MAXNUP),SPINUP(MAXNUP)
0023 c      SAVE /HEPEUP/
0024
0025 C...Read info from file.
0026 c      IF(MSTP(162).GT.0) THEN
0027 c        READ(MSTP(162),*,END=110,ERR=110) NUP,IDPRUP,XWGTUP,SCALUP,
0028 c     &  AQEDUP,AQCDUP
0029 c        DO 100 I=1,NUP
0030 c          READ(MSTP(162),*,END=110,ERR=110) IDUP(I),ISTUP(I),
0031 c     &    MOTHUP(1,I),MOTHUP(2,I),ICOLUP(1,I),ICOLUP(2,I),
0032 c     &    (PUP(J,I),J=1,5),VTIMUP(I),SPINUP(I)
0033 c  100   CONTINUE
0034 c        RETURN
0035 C...Special when reached end of file or other error.
0036 c  110   NUP=0
0037
0038 C...Else not implemented.
0039 c      ELSE
0040 c        WRITE(MSTU(11),5000)
0041 c        STOP
0042 c      ENDIF
0043
0044 C...Format for error printout.
0045 c 5000 FORMAT(1X,'Error: You have not implemented UPEVNT routine'/
0046 c     &1X,'Dummy routine in PYTHIA file called instead.'/
0047 c     &1X,'Execution stopped!')
0048
0049 c      RETURN
0050 c      END
0051
0052 C*********************************************************************
0053
0054 C...UPVETO
0055 C...Dummy routine, to be replaced by user, to veto event generation
0056 C...on the parton level, after parton showers but before multiple
0057 C...interactions, beam remnants and hadronization is added.
0058 C...If resonances like W, Z, top, Higgs and SUSY particles are handed
0059 C...undecayed from UPEVNT, or are generated by PYTHIA, they will also
0060 C...be undecayed at this stage; if decayed their decay products will
0061 C...have been allowed to shower.
0062
0063 C...All partons at the end of the shower phase are stored in the
0064 C...HEPEVT commonblock. The interesting information is
0065 C...NHEP = the number of such partons, in entries 1 <= i <= NHEP,
0066 C...IDHEP(I) = the particle ID code according to PDG conventions,
0067 C...PHEP(J,I) = the (p_x, p_y, p_z, E, m) of the particle.
0068 C...All ISTHEP entries are 1, while the rest is zeroed.
0069
0070 C...The user decision is to be conveyed by the IVETO value.
0071 C...IVETO = 0 : retain current event and generate in full;
0072 C...      = 1 : abort generation of current event and move to next.
0073
0074       SUBROUTINE UPVETO(IVETO)
0075
0076 C...HEPEVT commonblock.
0077       PARAMETER (NMXHEP=4000)
0078       COMMON/HEPEVT/NEVHEP,NHEP,ISTHEP(NMXHEP),IDHEP(NMXHEP),
0079      &JMOHEP(2,NMXHEP),JDAHEP(2,NMXHEP),PHEP(5,NMXHEP),VHEP(4,NMXHEP)
0080       DOUBLE PRECISION PHEP,VHEP
0081       SAVE /HEPEVT/
0082
0083 C...Next few lines allow you to see what info PYVETO extracted from
0084 C...the full event record for the first two events.
0085 C...Delete if you don't want it.
0086       DATA NLIST/0/
0087       SAVE NLIST
0088       IF(NLIST.LE.2) THEN
0089         WRITE(*,*) ' Full event record at time of UPVETO call:'
0090         CALL PYLIST(1)
0091         WRITE(*,*) ' Part of event record made available to UPVETO:'
0092         CALL PYLIST(5)
0093         NLIST=NLIST+1
0094       ENDIF
0095
0096 C...Make decision here.
0097       IVETO = 0
0098
0099       RETURN
0100       END