final state study Jaewon Park University of Rochester MINERvA/Jupiter Group Meeting, Feb 7, 2007

2 Processes involving with final state Proton and muon tracks will determi ne primary vertex Two gammas are from CC NC

3 ECAL for Generate single pi0 ev ent  Theta=0, 20cm from U S-ECAL  200MeV to 1GeV OD hit ignored Energy summed using dE/dx weighting

4 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 wit h each hits. Calculate gamma’s momentum from direction and energ y

5 Flowchart Two gammas’ center of energy w.r.t. primary vertex primary vertex dE/dx weighted energy deposit from truth hit Two gammas’ direction w.r.t. primary vertex Two gammas’ total energy deposit Two gammas’ 4-momentum Pi0’s 4-omentum Pi0’s mass

6 Sanity check Compare reconstructed gamma with truth info rmation Truth info Using center of energy Difference

7 Sanity check(2)

8 invariant mass It’ll be useful to use thi s quantity in filter out b ackground.

9 resolution Good agreement with ECAL calculation

10 NC RES events Two gammas’ res olution Each gamma ener gy > 100MeV

11 NC RES events – Pi0 resolution Reconstructed pi0 m ass peak is found at 128MeV (5% less tha n true value) True pi0 mass: 135M eV

12 Checking tracker data True pi0 vertex  1151/5000 selection eff: requires primary proton and primary pi0 and two gammas vPos(3) from tracker verte x result  326/5000: requires event =vevent and vMoth=0 51/5000 selection eff: co mbine two selections

13 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