Implication of W-Boson Charge Asymmetry Measurements in pp̅ Collisions for Models of Charge Symmetry Violations in Parton Distributions

A surprisingly large charge symmetry violation of the sea quarks in the nucleon has been proposed in a recent article by Boros et al. as an explanation of the discrepancy between neutrino and muon nucleon structure function data at low x. We show that these models are ruled out by the published CDF W charge asymmetry measurements, which strongly constrain the ratio of d and u quark momentum distributions in the proton over the x range of 0.006 to 0.34. This constraint also limits the systematic error from possible charge symmetry violation in the determinations of sin²θ_W from νN scattering experiments.