Muon reconstruction and identification efficiency in ATLAS using the full Run 2 pp collision data set at sqrt{s}=13 TeV

Abstract

This article documents the muon reconstruction and identification efficiency obtained by the ATLAS experiment for 139 hbox {fb}^{-1} of pp collision data at sqrt{s}=13 TeV collected between 2015 and 2018 during Run 2 of the LHC. The increased instantaneous luminosity delivered by the LHC over this period required a reoptimisation of the criteria for the identification of prompt muons. Improved and newly developed algorithms were deployed to preserve high muon identification efficiency with a low misidentification rate and good momentum resolution. The availability of large samples of Zrightarrow mu mu and J/psi rightarrow mu mu decays, and the minimisation of systematic uncertainties, allows the efficiencies of criteria for muon identification, primary vertex association, and isolation to be measured with an accuracy at the per-mille level in the bulk of the phase space, and up to the percent level in complex kinematic configurations. Excellent performance is achieved over a range of transverse momenta from 3 GeV to several hundred GeV, and across the full muon detector acceptance of |eta |<2.7.