Opened 8 years ago
Closed 8 years ago
#1009 closed Bug (fixed)
mother daughter relations
Reported by: | Sadia Khalil | Owned by: | |
---|---|---|---|
Priority: | minor | Milestone: | |
Component: | Delphes code | Version: | Delphes 3 |
Keywords: | Cc: |
Description
Dear all,
Is the class DelphesHepMCReader up to date w.r.t pythia8 parameters? Using the standard CMS configuration file (CMS_PhaseII_Substructure_200PU.tcl) to Delphes trees, and following the example Example5.C, I do not understand as how can I access the PDGID of mother and daughters of a particular decay, say top -> b W.
Thanks,
Sadia
Change History (2)
comment:2 by , 8 years ago
Resolution: | → fixed |
---|---|
Status: | new → closed |
I've checked CMS_PhaseII_Substructure_200PU.tcl and I think that I've found the source of the problem. This card has the GenParticleFilter module enabled. This module removes some generated particles. In this case, the mother and daughter indices become unusable.
The easiest solution is to replace
add Branch GenParticleFilter/filteredParticles Particle GenParticle
with
add Branch Delphes/allParticles Particle GenParticle
If M2 (or D2) is -1, then M1 (or D1) is the index of the mother (daughter). Otherwise M1 (or D1) is the index of the first mother (or daughter) and M2 (or D2) is the index of the last mother.
As far as I know there is nothing Pythia8 specific in the HepMC file format. However, it's possible that when converting from the HepMC vertices to the M1/M2 and D1/D2 indices some of them aren't calculated correctly.
Could you please provide more details about your problem?