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

Abstract

Abstract This article documents the muon reconstruction and identification efficiency obtained by the ATLAS experiment for 139

$$\hbox {fb}^{-1}$$

fb

- 1

of pp collision data at

$$\sqrt{s}=13$$

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

$$Z\rightarrow \mu \mu $$

Z → μ μ

and

$$J/\psi \rightarrow \mu \mu $$

J / ψ → μ μ

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

$$|\eta |<2.7$$

| η | < 2.7

.