First look at high pT electrons with v12

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First look at high pT electrons with v12
23 January 2007
Julien MOREL CSC note diphoton dilepton
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Data sets and Athena version

• We used
• Athena simu and reco version 12.0.3
• As we dont have any fully simulated Z in v12
• we first look at single electrons
• Data Sets
• calib0_csc11.007061.singlepart_e_E100.recon.AOD.v1
  2000301_tid003486
• calib0_csc11.007074.singlepart_e_E200.recon.AOD.v1
  2000301_tid003480
• calib0_csc11.007075.singlepart_e_E500.recon.AOD.v1
  2000301_tid003487
• Number of events
• 19000 electrons E 100 GeV
• 17850 electrons E 200 GeV
• 23000 electrons E 500 GeV

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Electron resolution and linearity E 100 GeV
Reso (1.3 0.03) Lin (0.4 0.04) was with
v11 Reso ? 1.1 Lin ? -0.5
Reso (1.5 0.09) Lin (0.5 0.12) was with
v11 Reso ? 1 Lin ? 0.5
Reso (5.5 0.3) Lin (9.2 0.35)
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Electron resolution and linearity E 200 GeV
Reso (0.9 0.05) Lin (0.2 0.07) was with
v11 Reso ? 1 Lin ? -0.5
Reso (1 0.07) Lin (0.15 0.09) was with
v11 Reso ? 1.2 Lin ? 0.5
Reso (4.9 0.4) Lin (9 0.3)
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Electron resolution and linearity E 500 GeV
Reso (0.8 0.03) Lin (0.2 0.03) was with
v11 Reso ? 0.9 Lin ? -0.5
Reso (0.9 0.07) Lin (0.2 0.08) was with
v11 Reso ? 1 Lin ? 0.5
Reso (4.9 0.3) Lin (9 0.3)
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Take a look at the linearity
Behavior in crack
In average for v11
Linearity in the barrel ? -0.5
Linearity in the end cap ? 0.5
Barrel under estimate energy End-cap over
estimate energy
In average for v12
Behavior in crack
Linearity in the barrel ? 0.3
Linearity in the end cap ? 0.3
Barrel and end cap seem to estimate energy in a
similar way
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Electron selection efficiency

• Selection efficiency
• 0.56 for 100 GeV (was ?0.68 with v11)
• 0.6 for 200 GeV (was ?0.74 with v11)
• 0.54 for 500 GeV (was ?0.75 with v11)

Tracker based identification (red) still the main
source of loss
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Electron selection efficiency vs eta
Crack is visible around 1.4 - 1.6 in ? ??1.8
seem to be another region with a low efficiency
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Conclusion and outlook
v12 gives results for energy resolution and
linearity in agreement with v11 The behavior in
the crack seems to be improved in
v12 Efficiencies look quite different, we need
electrons coming from Z to check

• Still to do
• Look at the trigger efficiencies
• We need v12 Z samples !!!