Umut Kose

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Neutrino interaction location in the OPERA
Experiment

• Umut Kose

Nagoya University
New Development of Flavor Physics, 10.03.2009,
Tennomaru, Gamagori
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Vertex location method
CSD found
direct VTX hunting method
scan back location method
scan back
volume scan around VTX prediction
point (1cm1cm10plates)?
volume scan around stop plate (1cm1cm10plates)
?
not found
VTX search
partner parent search
found
VTX located
Decay Search
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Scanback location Method
CS Doublet
5 mm
ECC Brick (57 emulsions 56 Pb)?
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Scanback location Method
CS Doublet
Stopping Plate
5 mm
ECC Brick (57 emulsions 56 Pb)?
The vertex is confirmed by scanning a volume
around the stopping position recording all the
track segments within a given angular acceptance
NetScan data taking. The fiducial volume is
1cm2x10 films in total.
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CS-ECC connections
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Direct Vertex Hunting
NetScan Fiducial Volume 1cm2x10 plates
ECC Brick
5 mm
CS Doublet
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How to analyse ECC data
Offline tracking and vertex reconstruction
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Summary of events
147 neutrino interaction vertex is located in ECC
bricks
147 events 116 CC 31 NC
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Position distributions
Y (mm)?
X(mm)?
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Vertex Plate distributions
All Events
NC Events
CC Events
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Multiplicity distributions
All Events
CC Events
NC Events
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Slope distributions
qy
qx
qx
qy
Space angle
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Summary

• In total about 500 events (EuropeJapan Scanning
  centers) located in ECC..
• Neutrino location chains from electronic detector
  to ECC working well..
• OPERA neutrino interaction location and tau decay
  search is going on
• The tau decay search will be introduced by the
  next speaker Nonoyama