pythiaeRHIC/pythia/pytaud.f

0001
0002 C*********************************************************************
0003
0004 C...PYTAUD
0005 C...Dummy routine, to be replaced by user, to handle the decay of a
0006 C...polarized tau lepton.
0007 C...Input:
0008 C...ITAU is the position where the decaying tau is stored in /PYJETS/.
0009 C...IORIG is the position where the mother of the tau is stored;
0010 C...     is 0 when the mother is not stored.
0011 C...KFORIG is the flavour of the mother of the tau;
0012 C...     is 0 when the mother is not known.
0013 C...Note that IORIG=0 does not necessarily imply KFORIG=0;
0014 C...     e.g. in B hadron semileptonic decays the W  propagator
0015 C...     is not explicitly stored but the W code is still unambiguous.
0016 C...Output:
0017 C...NDECAY is the number of decay products in the current tau decay.
0018 C...These decay products should be added to the /PYJETS/ common block,
0019 C...in positions N+1 through N+NDECAY. For each product I you must
0020 C...give the flavour codes K(I,2) and the five-momenta P(I,1), P(I,2),
0021 C...P(I,3), P(I,4) and P(I,5). The rest will be stored automatically.
0022
0023       SUBROUTINE PYTAUD(ITAU,IORIG,KFORIG,NDECAY)
0024
0025 C...Double precision and integer declarations.
0026       IMPLICIT DOUBLE PRECISION(A-H, O-Z)
0027       IMPLICIT INTEGER(I-N)
0028       INTEGER PYK,PYCHGE,PYCOMP
0029 C...Commonblocks.
0030       COMMON/PYJETS/N,NPAD,K(4000,5),P(4000,5),V(4000,5)
0031       COMMON/PYDAT1/MSTU(200),PARU(200),MSTJ(200),PARJ(200)
0032       SAVE /PYJETS/,/PYDAT1/
0033
0034 C...Stop program if this routine is ever called.
0035 C...You should not copy these lines to your own routine.
0036       NDECAY=ITAU+IORIG+KFORIG
0037       WRITE(MSTU(11),5000)
0038       CALL PYSTOP(10)
0039
0040 C...Format for error printout.
0041  5000 FORMAT(1X,'Error: you did not link your PYTAUD routine ',
0042      &'correctly.'/1X,'Dummy routine in PYTHIA file called instead.'/
0043      &1X,'Execution stopped!')
0044
0045       RETURN
0046       END