Measurement of the muon charge asymmetry in $p\\bar{p}$ $\\to$ W+X $\\to$ $\\mu$$\\nu$ + X events at $\\sqrt{s}$=1.96??????TeV

We present a measurement of the muon charge asymmetry from the decay of the W boson via W -> mu nu using 7: 3 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider at root s = 1.96 TeV. The muon charge asymmetry is presented in two kinematic regions in muon transverse momentum and event missing transverse energy: (p(T)(mu) > 25 GeV, E-T > 25 GeV) and (p(T)(mu) > 35 GeV, E-T > 35 GeV). The measured asymmetries are compared with theory predictions made using three parton distribution function sets. The data at p(T)(mu) > 35 GeV, E-T > 35 GeV, and larger values of vertical bar eta(mu)vertical bar favor an increased d(x)/u(x) ratio at higher values of x than is predicted.