NA-ATLAS mtg

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NA-ATLAS mtg
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Experience from the Tevatron Chlebana FNAL
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Experience from the Tevatron Chlebana FNAL
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Experience from the Tevatron Chlebana FNAL
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Experience from the Tevatron Chlebana FNAL
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Jet Tagging and Jet Veto
Rate of leading jet in Z?ee,?? jets after
central jet veto

• Z ?ee,?? jets gives a large statistics sample
  for the calibration of jets all the way to the
  forward region
• Signal extraction does not depend directly on jet
  energy scale. Enough to have 5 (10) energy
  scale uncertainty for central (forward) jets
• Study central jet veto with same sample

See W.Quayles talk
Mellado Performance requirements
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Huston
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Huston
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Huston
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(No Transcript)
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Seuster Jet/Et-miss
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Technique
Narain b-tagging

• Quite a few Taggers are available
• Impact Parameter based taggers (IP2D, IP3D)
• Secondary vertex reconstruction based
• Provide discrimination based on a comparison
  between two hypotheses
• likelihood for a jet to originate from a b-quark
  (b)
• 
  OR a light-quark/gluon (u)
• For each discriminating variable x in a tagger,
  build calibration functions for the two
  hypotheses
• Pb(x) and Pu(x)
• The final discriminating variable (jet level)
• W ?x ln(Pb (x) /Pu (x))
• Large W high probability that the jet
  originates from a b quark

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Performance ( )
J.-B. de Vivie, V.Kostyukhin A. Rozanov, L
Vacavant

• H events
• Model u-jets using ttjj
• release 10.0.1
• High eff crucial eb4

SV1IP3D IP3D IP2D Lifetime2D lhSig
Ru (eb50) Ru (eb60)
IP2D 192 2 61 1
SV1IP3D 610 12 229 3
as a function of pT and ? _at_ 60
efficiency
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Planned Improvements

• goal to reach eb70 with Ru100
• A few planned improvements
• (Some are already in 11.X.0 or will be in
  release 12)
• combine space and soft leptons in jets
• K0 and ?0 impact parameters, no direct tracks IP
• New tracking
• track quality classification
• multiple secondary vertices
• shared/ambiguous hits, kill interactions

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Software Changes
L Vacavant

• Transition from JetTag (previous) and
  ParticleJet (new)
• A single collection for jets (calobtagging
  information)
• In the 11.X.0 branch
• Implies that previous AOD not readable w/ new
  release.
• For previous btagging
• All releases 11.0.X are OK
• Recommended 11.0.4(,1,2)
• For new btagging
• 11.4.0 not recommended
• 11.5.0
• Will be useable for b-tagging, including soft
  lepton taggers
• 12.0.0 scheduled for 1st half of May
• possible to run new btagging in 11.0.4(1,2)

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Beam xing angle
1 GeV
Half-angle 143mrad vertical (CMS same angle,
horizontal)