TopPairPlusGamma/AnalysisTools — pull request #14 by phy6phs (2013-09-05 16:13:41+00:00)
Title: know where photon comes from in madgraph

Read the gen particle information to see where photon in MG sample comes from. Either signal (unlikely, from proton, t,b or W), from a lepton in the event that decayed from the W (BG) or fake (from another source.