Event Reconstruction

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Event Reconstruction
Andy Blake Cambridge University
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Introduction
Cambridge Reconstruction Software

• AtNuReco track / shower reconstruction
  software in development
• Version 1.0 now in CVS

Basic themes

• Track / shower reconstruction provides initial
  separation of ?µ CC / ?e CC
• Track / shower reconstruction carried out
  simultaneously

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AtNuReco Algorithm
Tracks
Showers
Seeds
Seeds
Segments
Clusters
2D
2D Showers
2D Tracks
3D
3D Tracks
3D Showers
CandTracks
CandShowers
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Atmos Nu Studies

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

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?µ CC reco efficiency
AtNuReco
SR
green track red shower only
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?e CC reco efficiency
AtNuReco
SR
green track red shower only
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NC reco efficiency
AtNuReco
SR
green track red shower only
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shower-like events
?e CC event
?µ CC event
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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-talk
digit charge with X-talk
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Demultiplexing

• Comparing demultiplexed strips with MC truth
  mask
• All events that pass demultiplexing

strip charge - without X-talk
strip charge - with X-talk
light blue correct strips dark blue incorrect
strips
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correct charge - without X-talk
correct charge - with X-talk
Correlation of correct charge with without
X-talk
with X-talk
lt 0.9 gt 0.9
lt 0.9 2 1
gt 0.9 3 94
without X-talk
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Track Reconstruction

• Compare reconstructed tracks with MC truth masks
• All ?µ CC tracks

track quality without X-talk
track quality with X-talk
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Correlation of track quality with without X-talk
with X-talk
no trk shw
no 10 1 4
trk 1 60 5
shw 0 1 18
without X-talk
with X-talk
Qlt0.8 Qgt0.8
Qlt0.8 18 2
Qgt0.8 2 78
without X-talk
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Typical showery ?µ CC event
without X-talk
with X-talk
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Conclusion

• Track / shower reconstruction still room for
  improvement
• Crosstalk no evidence of significant degradation
  so far