Precision measurement of the muon charge asymmetry from $W$-boson decays in $pp$ collisions at $\sqrt{s}$ = 13 TeV in the forward region

TL;DR

This paper reports a highly precise measurement of muon charge asymmetry from W-boson decays in proton-proton collisions at 13 TeV, using LHCb data, aligning well with advanced QCD predictions.

Contribution

It provides the most accurate forward-region muon charge asymmetry measurement to date, enhancing constraints on proton structure and QCD models.

Findings

Most precise muon charge asymmetry measurement in the forward region

Results agree with next-to-next-to-leading-order QCD predictions

Data covers muons with 25-55 GeV transverse momentum and 2.0-4.5 pseudorapidity

Abstract

A precision measurement of the muon charge asymmetry from $W$-boson decays in proton-proton collisions at $\sqrt{s}$ = 13 TeV is presented. The analysis utilizes data corresponding to an integrated luminosity of 5.1 $fb^{-1}$, recorded by the LHCb detector during 2016, 2017 and 2018. The asymmetry is measured for muons with transverse momentum between 25 and 55 GeV and pseudorapidity between 2.0 and 4.5. This result represents the most precise determination of the muon charge asymmetry in the forward region to date, exhibiting excellent agreement with next-to-next-to-leading-order predictions in perturbative quantum chromodynamics.