Gen muons from taus

It is customary in DY analyses to reject muons (and electrons) form the decay of tau leptons. A flag for this needs to be computed in the Ntupliser and added to the trees (gen muons are still needed for the Rochester correction).

I'm not sure how this additional flag would fit in the current class hierarchy. The perfect solution would be:

BaseMuon(p4, charge)
  GenMuon(originatesFromTau)
  RecMuon(selectors)

This also looks a bit complicated (we're slowly reinventing the CMSSW class hierarchy).

added To Do label

changed milestone to %Adapt software for Zμμγ after PO&DAS23

added to epic &1

added On hold label and removed To Do label

Actually, given that the DY samples are split between µµ and ττ final states, this is not needed for now. It would be if we wanted to use MadGraph samples.

added changeminor typephysics labels

mentioned in issue #152 (closed)