Abstract
The differential cross section and charge asymmetry for inclusive $pp \to W^{\pm} + X \to \mu^{\pm}ν + X$ production at $\sqrt{s} = 8\mathrm{\,Te\kern -0.1em V}$ are measured as a function of muon pseudorapidity. The data sample corresponds to an integrated luminosity of 18.8 fb$^{−1}$ recorded with the CMS detector at the LHC. These results provide important constraints on the parton distribution functions of the proton in the range of the Bjorken scaling variable x from 10$^{−3}$ to 10$^{−1}$.