Measurement of the W boson mass

TheWboson mass is measured using proton-proton collision data at $$ \sqrt{s} $$s = 13 TeV corresponding to an integrated luminosity of 1.7 fb⁻¹recorded during 2016 by the LHCb experiment. With a simultaneous fit of the muonq/p_Tdistribution of a sample ofW→μνdecays and theϕ^*distribution of a sample ofZ→μμdecays theWboson mass is determined to be $$ {m}_w=80354\pm {23}_{\mathrm{stat}}\pm {10}_{\mathrm{exp}}\pm {17}_{\mathrm{theory}}\pm {9}_{\mathrm{PDF}}\mathrm{MeV}, $$mw=80354±23stat±10exp±17theory±9PDFMeV, where uncertainties correspond to contributions from statistical, experimental systematic, theoretical and parton distribution function sources. This is an average of results based on three recent global parton distribution function sets. The measurement agrees well with the prediction of the global electroweak fit and with previous measurements.