Measurements of the associated production of a W boson and a charm quark in proton–proton collisions at sqrt{s}=8,text {TeV}

Abstract

Measurements of the associated production of a W boson and a charm ({text {c}}) quark in proton–proton collisions at a centre-of-mass energy of 8,text {TeV} are reported. The analysis uses a data sample corresponding to a total integrated luminosity of 19.7,text {fb}^{-1} collected by the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm quark jets are selected using distinctive signatures of charm hadron decays. The product of the cross section and branching fraction sigma (text {p}text {p}rightarrow text {W}+ {text {c}}+ text {X}) {mathcal {B}}(text {W}rightarrow ell upnu ), where ell = text {e} or upmu , and the cross section ratio sigma (text {p}text {p}rightarrow {{text {W}}^{+} + bar{{text {c}}} + text {X}}) / sigma (text {p}text {p}rightarrow {{text {W}}^{-} + {text {c}}+ text {X}}) are measured in a fiducial volume and differentially as functions of the pseudorapidity and of the transverse momentum of the lepton from the W boson decay. The results are compared with theoretical predictions. The impact of these measurements on the determination of the strange quark distribution is assessed.