Measurements of the associated production of a W boson and a charm quark in proton-proton collisions at s = 8 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 $\sigma (\text{pp}\to \text{W}+\text{c}+\text{X})B(\text{W}\to \ell \nu )$ , where $\ell =\text{e}$ or $\mu$ , and the cross section ratio $\sigma (\text{pp}\to {\text{W}}^{+}+\overline{\text{c}}+\text{X})/\sigma (\text{pp}\to {\text{W}}^{-}+\text{c}+\text{X})$ 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.