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 (c) quark in proton–proton collisions at a centre-of-mass energy of 8 TeV are reported. The analysis uses a data sample corresponding to a total integrated luminosity of 19.7 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 σ (pp → W + c + X)B(W → ν), where = e or μ, and the cross section ratio σ (pp → W+ + ¯c + X)/σ (pp → W− + c + X) are measured in a fiducial volume and differ entially as functions of the pseudorapidity and of the trans verse 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.