A first glance at the ACD simulation

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A first glance at the ACD simulation
Francesco Loparco INFN - Bari
(see also Stefanos presentation)
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Overview

• Aim of this work
• look at the ACD variables and learn their meaning
  
• consistency check in order to find eventual bugs
  in the simulation
• get ready for ACD data analysis
• MC simulated data samples
• /nfs/farm/g/glast/u11/InstrumentAnalysis/MC/Engine
  eringModel-v5r0703p3/LAT_Surface_Muons/surface_muo
  ns_1M_svac.root
• /nfs/farm/g/glast/u11/InstrumentAnalysis/MC/Engine
  eringModel-v5r0703p3/LAT_Surface_Muons/surface_muo
  ns_1M_merit.root

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Digits hits
A hit is produced if the veto discriminator is
set ? Ndigit Nhit
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ACD hit maps
top tiles
ribbons
sidewalls
ACD sidewalls top ? bottom
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Energy loss path length in the ACD
µ crossing a single tile
No reconstructed tracks by the TKR
µ crossing two tiles
1 tile (10mm thick)
1 tile (12mm thick)
2 tiles
ribbons
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Energy loss per unit path length

• badly reconstructed tracks
• multiple reconstructed tracks with fake
  intersections with the ACD tiles
• tracks close to the ACD corners, with errors in
  the evaluation of the path length

???
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Energy loss for single muon events
Single muon cut TkrNumTracks1
AcdActiveDistance gt 5mm
Multiple tracks and events crossing the ACD tiles
near the corner regions have been ruled out. The
peak for low ?E is now due only to bad
reconstructed tracks
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ACD-TKR intersections (1)
Expectation Ntrack Nint 2Ntrack
Events with Nint gt 2Ntrack tracks crossing
overlapping tiles
Very few events with Nint lt Ntrack bad track
reconstruction?
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ACD-TKR intersections (2)
Sidewalls
Top tiles
Overlapping tiles
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ACD-TKR intersections (3)
The map of intersections shows overlapping tiles
and ribbons
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Conclusions Acknowledgements

• A study of the ACD variables has been carried out
  on a sample of MC simulated muons
• No significant deviations from expectations have
  been found

Thanks to Eric for his ospitality and for his
patience in answering all my questions!