1. Event Reconstruction Andy Blake Cambridge University

2. Introduction “AtNuReco” track / shower reconstruction software in development Version 1.0 now in CVS Cambridge Reconstruction Software Basic themes Track / shower reconstruction provides initial separation of ν µ CC / ν e CC Track / shower reconstruction carried out simultaneously

3. AtNuReco Algorithm Seeds SegmentsClusters TracksShowers 2D Showers2D Tracks 2D 3D Tracks3D Showers 3D CandTracksCandShowers

4. Atmos Nu Studies 20,000 MC atmospheric neutrinos (run 110) 4/5 plane trigger Cambridge demultiplexer AtNuReco + SR reconstruction Studies of reco efficiencies + crosstalk

5. ν µ CC reco efficiency AtNuRecoSR green = track red = shower only

6. ν e CC reco efficiency AtNuRecoSR green = track red = shower only

7. NC reco efficiency AtNuRecoSR green = track red = shower only

8. shower-like events ν e CC eventν µ CC event

9. Crosstalk Studies DetSim package (N.Tagg) implements crosstalk model from gminos in offline framework. Additional 0.05% crosstalk between all pixels of any PMT. digit charge – without X-talkdigit charge – with X-talk

10. Demultiplexing light blue = correct strips dark blue = incorrect strips Comparing demultiplexed strips with MC truth mask All events that pass demultiplexing strip charge - without X-talkstrip charge - with X-talk

11. % correct charge - without X-talk% correct charge - with X-talk Correlation of % correct charge with + without X-talk < 0.9> 0.9 < 0.921 > 0.9394 with X-talk without X-talk

12. Track Reconstruction Compare reconstructed tracks with MC truth masks All ν µ CC tracks track quality – without X-talktrack quality – with X-talk

13. Correlation of track quality with + without X-talk notrkshw no1014 trk1605 shw0118 with X-talk without X-talk Q<0.8Q>0.8 Q<0.8182 Q>0.8278 with X-talk without X-talk

14. Typical showery ν µ CC event without X-talk : with X-talk :

15. Conclusion Track / shower reconstruction: still room for improvement Crosstalk: no evidence of significant degradation so far