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background studies for GMSB. Andrea Bangert Santa Cruz Institute for Particle Physics May 6 th , 2010. object definitions. all photons: pT > 20 GeV |eta| < 2.5 signal photons: “gammas” isEM::TightPhoton == 0 Control sample photons: “QCD” pass loose EM but not tight isEM criteria
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background studies for GMSB Andrea Bangert Santa Cruz Institute for Particle Physics May 6th, 2010
object definitions • all photons: • pT > 20 GeV • |eta| < 2.5 • signal photons: “gammas” • isEM::TightPhoton == 0 • Control sample photons: “QCD” • pass loose EM but not tight isEM criteria • (isEM::LoosePhoton == 0) && (isEM::TightPhoton != 0) • question: how effective is this criteria for selecting “control” photons?
samples • two signal photons: • “gamma-gamma” • one signal photon, one “control” photon: • “gamma-QCD” • two “control” photons: • “QCD” • goal: collect a “QCD sample” which we can use to model the background due to events without true MET • question: will “QCD” events be in the event stream?
estimates • only cuts on photon objects have been made • two photon objects were required • no cuts were made on MET or HT • need to require g20_loose or 2g10_loose trigger to fire. • will this collect “QCD” events? • need to know how cut on HT affects sample populations. • need to use cross sections, scale to L = 1 pb-1