Physics at LHC conference 7 June 2010, T. Cornelissen 1 Thijs Cornelissen (INFN Genova) Thijs Cornelissen (INFN Genova) On behalf of the ATLAS collaboration On behalf of the ATLAS collaboration Muon Muon reconstruction reconstruction performance in performance in ATLAS ATLAS
18
Embed
Thijs Cornelissen (INFN Genova ) On behalf of the ATLAS collaboration
Muon reconstruction performance in ATLAS. Thijs Cornelissen (INFN Genova ) On behalf of the ATLAS collaboration. Outline. The ATLAS detector Muon performance with cosmics Muon performance with collision events. The Inner Detector (or inner tracker). - PowerPoint PPT Presentation
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Basic track parameter distributions show good agreement between data and simulationSimulation shows contributions from prompt muons (including b/c decays) in red, early /K decays in green, late decays in white
Physics at LHC conference 7 June 2010, T. Cornelissen
P 11
Number of ID hits on track well described by simulation (see presentation by T. Kuhl)Good agreement between data and simulation concerning number of MDT and CSC hits on track
Number of hits on trackNumber of hits on track
combined muons
2 stations
3 stations
ATLAS preliminary ATLAS preliminary
Physics at LHC conference 7 June 2010, T. Cornelissen
P 12
Reconstruction efficiencies estimated by
comparing overlap between algorithms
Use tagged muons that are confirmed as
calorimeter muons, check if combined
algorithm found the muon
Efficiencies underestimated due to
contamination of sample by /K decays
Decays are often rejected by combined
algorithms
Ultimately, efficiencies will be determined
using tag&probe with resonances
First efficiency measurementsFirst efficiency measurements
ATLAS preliminary
Physics at LHC conference 7 June 2010, T. Cornelissen
P 13
Resolution of MS tracks studied by
comparing momentum with ID
track
Expected resolution ~5% for MS
tracks, ~2.5% for ID tracks (on
average)
Asymmetric tail due to /K decays,
larger in data than in simulation
Under investigation
Momentum resolutionMomentum resolution
ATLAS preliminary
Physics at LHC conference 7 June 2010, T. Cornelissen
P 14
Muons inside jets have much
larger energy deposits around
them
Excellent data/MC agreement
concerning energy deposits
Simulation can thus be used to
optimize isolation cuts
Muon energy deposit and isolationMuon energy deposit and isolationTra
ck
isola
tion
Calo
rim
ete
r is
ola
tion
ATLAS preliminary
ATLAS preliminary
ATLAS preliminary
Physics at LHC conference 7 June 2010, T. Cornelissen
P 15
• First 0.6 nb-1 has been used to assess the performance of the ATLAS muon reconstruction
• Relative efficiency measurements, muon isolation studies show very good data/MC agreement
• Now working towards full program using J/s and Zs
ConclusionsConclusions
Physics at LHC conference 7 June 2010, T. Cornelissen
P 16
Backup
Physics at LHC conference 7 June 2010, T. Cornelissen
P 17
Composition in MC truthComposition in MC truth
ATLAS preliminary
Physics at LHC conference 7 June 2010, T. Cornelissen
P 18
7/4/2010
State of ATLAS for first 7 TeV State of ATLAS for first 7 TeV collisionscollisions