  The differential cross section and charge asymmetry for inclusive pp to W + X
to mu + neutrino + X production at sqrt(s) = 8 TeV are measured as a function
of muon pseudorapidity. The data sample corresponds to an integrated luminosity
of 18.8 inverse femtobarns 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 10E-3 to 10E-1.
