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.