P0D reconstruction/analysis update LE PHUOC TRUNG

Software activities A new stable release of nd280 for TPC test beam MDC0 status: waiting to access the MC datasets P0D software: Continued reconstruction work: improve 0 purity, working on improving 0 reconstruction. Electron neutrino reconstruction: wait for kinematics files from H. Tanaka. Testing the midas (electronics output format) to root converter. Prepare software for cosmic data processing: reconstruction, calibration constant calculation.

Muon decay tagging update 58 ns Beam After spill 100 ns MUON DECAY TAGGING CC  interaction, - not reconstructed P0D xz or yz Clustering seed Later bunches After spill Expand clustering seed into later hits, hits added to the cluster are decay hits Make sure decay hits are distance connected 9cm, time connected 20ns Event with 2 or more decay hits is considered CC interaction. Tagging efficiency 50%, including muon capture, next slide Before 37%, bug

Muon capture Muon capture also produces delayed hits 4000 decays 4000 captures Composition of delayed hits Muon generated at 0.0 ns, plot from 100.0 ns Neutron spectrum From nucleus de-excitation, GEANT4 ‘not ideal’ Delayed hits from muon capture MeV

Delayed hits from NC single 0 production 16,000 single NC 0 not understood NC single 0 can be mistaken as muon decay

Short track detection Detect the longer side using Hough transform Make that the longer side is muon-like by counting the number of hits in each layers. Find the short side by angular scanning at both ends of the longer side. The short side appear as a peak in the angular histogram. Make sure that the open angle > 15 degrees, and no more than 2 hits within the open angle. Make sure that there are fewer than 5 remaining hits not associated with the V. First found by the Hough transform Angular histogram around these points

0 purity update MC: single NEUT /spill, 100,000 spills Include the new muon decay tagging Include the short track detection Efficiency: 18% Purity: ~ 47% 21% before 35% 32% 47% Reconstructed Energy (MeV)

Efficiency loss by different cuts Charged-current - rejection efficiency 99.8% =========================================== Particle 0 - All 1067 69420 Muon-like cut 1029 33038 Unmatched 993 26291 Muon decay cut 906 17606 Low hits cut 775 8393 Shower cut 496 3787 Invariant cut 286 1385 Fiducial cut 198 135 counts %  0 loss by cuts 38 3.56 36 3.37 87 8.15 131 12.28 279 26.15 210 19.68 88 8.25 198 18.56 CUTS 15% Room for efficiency improvement

0 reconstruction challenge

0 reconstruction summary Current implementation was originally written by K.Kobayashi, partly rewritten by Clark/Trung. Work need to be done: Improve vertex finder Energy reconstruction/calibration Energy leaking study Deviation from true vertex  ~ 3cm  ~ 4cm  ~ 0.1 Energy resolution, 350 MeV, fully contained 0

SUMMARY Improve muon decay tagging Neutrons in NC interactions cause 0 mistaken as muon decay. Short track detection What needs to be improved: 0 reconstruction