[Halld-offline] geant particle ids

[Beni Zihlmann]

Hi All,

Upon request:
I committed changes to bggen, hdgeant and particleType.h in order for the
use to be able to let omega, phi, eta', and the three rhos decay in geant.
the pid number are:

Geant  Pythia
-------------------------------------
  33       223    ! omega(783)
  34       331    ! eta prime
  35       333    ! PHI
  42      113    ! rho0
  43      213    ! rho+
  44      -213   ! rho-


If you use bggen with the current pythia-geant.map translation table
omega, phi and eta' are decayed by geant and their pids will appear in
DMCThrown as well as their decay products with the appropriate association.


At this point I would like to make a comment. Generally it is not a good 
idea to let
geant decay particles it is not designed for that. Phythia however is 
exactly desinged
to do that. What we should do in the future, maybe when we move to 
geant4 is to
change the code in DANA to take the full pythia output and create the 
proper relation
between daughter and parent particles for the user such that the user 
does not have
to do it him/her- self.


cheers,
Beni