title: Prospects for improving the LHC W boson mass measurement with forward muons.
abstract: Measurements of theWboson mass are planned by the ATLAS and CMS experiments, but for the time being, these may be unable to compete with the current world average precision of 15 MeV, due to uncertainties in the PDFs. We discuss the potential of a measurement by the LHCb experiment based on the charged lepton transverse momentum [Formula: see text] spectrum in [Formula: see text] decays. The unique forward acceptance of LHCb means that the PDF uncertainties would be anti-correlated with those of [Formula: see text] based measurements by ATLAS and CMS. We compute an average of ATLAS, CMS and LHCb measurements of [Formula: see text] from the [Formula: see text] distribution. Considering PDF uncertainties, this average is a factor of 1.3 more precise than an average of ATLAS and CMS alone. Despite the relatively low rate ofWproduction in LHCb, we estimate that with the Run-II dataset, a measurement could be performed with sufficient experimental precision to exploit this anti-correlation in PDF uncertainties. The modelling of the lepton-pair transverse momentum distribution in the neutral current Drell-Yan process could be a limiting factor of this measurement and will deserve further studies.
authors.affiliation: Dipartimento di Fisica, Sezione di Milano, Università degli Studi di Milano and INFN, Via Celoria 16, 20133 Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Bozzi
authors.affiliation: Dipartimento di Fisica, Universita degli Studi di Milano, Via Celoria 16, 20133 Milan, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Citelli
authors.affiliation: Physikalisches Institut, Ruprecht-Karls-Universitat, Im Neuenheimer Feld, 226, 69120 Heidelberg, Germany.
authors.forename: Mika
authors.initials: M
authors.lastname: Vesterinen
authors.affiliation: Dipartimento di Fisica, Universita degli Studi di Milano and INFN Sezione di Milano and TIF Lab, Via Celoria 16, 20133 Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vicini