[EvtGen] #1: Updating Pythia Particle Properties faulty in R01-07-00

[EvtGen]

#1: Updating Pythia Particle Properties faulty in R01-07-00
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  Reporter:  Martin Ritter  |      Owner:  jback
      Type:  defect         |     Status:  accepted
  Priority:  critical       |  Milestone:  R01-08-00
Resolution:                 |   Keywords:
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Comment (by guest):

 Thanks for the quick work. The changes seems to fix the issues explained
 in the ticket but I have some additional questions:

 1. Have I understood it correctly that the updates were not propagated to
 Pythia at all since the ParticleData was copied and not modified in place?
 So R01-07-00 is not affected by the `getMass()` but as it is as it doesn't
 update the particle properties of Pythia anyway?
 2. So I added some debug output again and some of the updates are a bit
 weird for me, for example:
    {{{
 EvtGen: Updating Pythia particle mass
    from: CMshower (94)
      to: W+copy (94)
     old: 8.03850000e+01
     new: 0.00000000e+00
 EvtGen: Updating Pythia particle width
    from: CMshower (94)
      to: W+copy (94)
     old: 2.08500000e+00
     new: 0.00000000e+00
     }}}
     (old = pythia original value, new = after update)
     now I have no idea if the W+copy is actually used by Pythia and if
 this change affects anything but wouldn't it make sense to exclude the PDG
 codes 81-100 from this update procedure as they are "reserved for
 generator-specific pseudoparticles and concepts"
 ([[http://pdg.lbl.gov/2017/reviews/rpp2017-rev-monte-carlo-
 numbering.pdf|pdg2017]])?

--
Ticket URL: <https://evtgen.hepforge.org/trac/ticket/1#comment:5>
EvtGen <http://evtgen.hepforge.org/>
EvtGen is a Monte Carlo generator of particle decays, in particular the weak decays of heavy flavour particles such as B mesons.