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Incorrect treatment of documentation lines in Geant4InputHandling #387
We observed a sever bug in events with charged lepton pairs - in particular w/ taus.
here only the last tau+, tau-, gamma should have been given to geant4, but we include also the previous tau parents ( that have zero lifetime in the input file). This also causes the tau lifetime to be applied n-times by geant4, as geant4 treats this as a decay chain.
The particles you refer to have generator status 2, right? That is not documentation.
Basically you want to reject taus (and maybe other things we discover later on) with 0 lifetime but keep other particles with 0 life time?
Have you tried taking the changes out and seeing what happens?
I guess the problem is that Pythia (and other generators?) are not using genstat==2 for decays only but also for 'documentation' where they then assign a lifetime of 0.
Do the short lived hadrons (eta_prime) that you used in testing your fix have 'exactly 0' lifetime or only such a small lifetime that they where falsely identified as having 0 lifetime ?
or put in the old code and fix the check for zero lifetime...
PS: We did verify that in our testproduction w/ v01-19-05, ie before your patch, the samples w/ lepton pairs where correct.