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This study focuses on understanding processes involving final states, specifically protons, muons, and gammas, using data from MINERvA/Jupiter Group Meeting. Various calculations and comparisons are made using truth and reconstructed information to analyze the properties of these particles.
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final state study Jaewon Park University of Rochester MINERvA/Jupiter Group Meeting, Feb 7, 2007
Processes involving with final state • Proton and muon tracks will determine primary vertex • Two gammas are from NC CC
ECAL for • Generate single pi0 event • Theta=0, 20cm from US-ECAL • 200MeV to 1GeV • OD hit ignored • Energy summed using dE/dx weighting
Processes involving with final state • Truth primary vertex is used • Didn’t require minimum angle between two gammas • I used truth information to know which gammas is associated with each hits. • Calculate gamma’s momentum from direction and energy
Flowchart dE/dx weighted energy deposit from truth hit primary vertex Two gammas’ center of energy w.r.t. primary vertex Two gammas’ total energy deposit Two gammas’ direction w.r.t. primary vertex Two gammas’ 4-momentum Pi0’s 4-omentum Pi0’s mass
Sanity check • Compare reconstructed gamma with truth information Truth info Using center of energy Difference
invariant mass • It’ll be useful to use this quantity in filter out background.
resolution • Good agreement with ECAL calculation
NC RES events • Two gammas’ resolution • Each gamma energy > 100MeV
NC RES events – Pi0 resolution • Reconstructed pi0 mass peak is found at 128MeV (5% less than true value) • True pi0 mass: 135MeV
Checking tracker data • True pi0 vertex • 1151/5000 selection eff: requires primary proton and primary pi0 and two gammas • vPos(3) from tracker vertex result • 326/5000: requires event=vevent and vMoth=0 • 51/5000 selection eff: combine two selections
Next step • Determine primary vertex from proton track • Need to check definition of ntuple • Scintillator bar ID can be used in stead of using truth hit position