I have root file with THashList containing different histograms TH1F, TH2F, TH3F, TH1I and I need to get from them some information about four-momentum of particles. I’m beginner and probably my question is stupid but where do start? I don’t know the details of the file and histograms contained in it. What do I need to pay attention?


the question probably is a bit ill defined. I guess the histograms have been filled with the value of some properties of some particles. It is not possible to reconstruct the four momentum of the particles that probably were in a ntuple/ttree.