Muon Reconstruction Performance

The performance of the ATLAS muon reconstruction and identification is studied with 17 nb−1 of LHC p-p collision data at $\sqrt{s}$=7 TeV collected with muon triggers. The selected muons have on average a momentum of 11 GeV and a transverse momentum of 4.5 GeV and are predominantly produced in weak decays of light hadrons and of hadrons containing b and c quarks. With such single muon events, the redundancy in the ATLAS muon reconstruction allows performance measurements by comparing different identification and reconstruction algorithms. Relative muon efficiencies and the momentum scale and resolution are studied. Also an estimate is given for the probability to reconstruct a (decayed) pion as muon, which is the most abundant muon background. The results are compared to Monte Carlo simulation, and a good agreement is found within the available statistical precision.