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

TL;DR

This paper reports measurements of W boson and charm quark associated production at 8 TeV proton-proton collisions, providing insights into the strange quark distribution and testing theoretical models.

Contribution

It presents the first detailed measurements of W + charm production cross sections and ratios at 8 TeV, including differential distributions, and compares them with theoretical predictions.

Findings

Measured cross sections and ratios for W + c production.

Compared experimental results with theoretical models.

Assessed impact on strange quark distribution.

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 $\sigma$(pp $\to$ W + c + X) $\mathcal{B}$(W $\to$ $\ell\nu$), where $\ell$ = e or $\mu$, and the cross section ratio $\sigma$(pp $\to$ W$^+$ + c + X) / $\sigma$(pp $\to$ W$^-$ + $\mathrm{\bar{c}}$ + X) are measured inclusively 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.