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

Abstract

Abstract Measurements of the associated production of a W boson and a charm ( $${\text {c}}$$ c ) quark in proton–proton collisions at a centre-of-mass energy of 8 $$\,\text {TeV}$$ TeV are reported. The analysis uses a data sample corresponding to a total integrated luminosity of 19.7 $$\,\text {fb}^{-1}$$ 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 $$\sigma (\text {p}\text {p}\rightarrow \text {W}+ {\text {c}}+ \text {X}) {\mathcal {B}}(\text {W}\rightarrow \ell \upnu )$$ σ ( pp → W + c + X ) B ( W → ℓ ν ) , where $$\ell = \text {e}$$ ℓ = e or $$\upmu $$ μ , and the cross section ratio $$\sigma (\text {p}\text {p}\rightarrow {{\text {W}}^{+} + \bar{{\text {c}}} + \text {X}}) / \sigma (\text {p}\text {p}\rightarrow {{\text {W}}^{-} + {\text {c}}+ \text {X}})$$ σ ( pp → W + + c ¯ + X ) / σ ( pp → W - + c + 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.