Implication of W-boson Charge Asymmetry Measurements in p-pbar Collisions for Models of Charge Symmetry Violations in Parton Distributions

摘要

A surprisingly large charge symmetry violation of the sea quarks in thenucleon has been proposed in a recent article by Boros et al. as an explanationof the discrepancy between neutrino (CCFR) and muon (NMC) nucleon structurefunction data at low x. We show that these models are ruled out by thepublished CDF W charge asymmetry measurements, which strongly constrain theratio of d and u quark momentum distributions in the proton over the x range of0.006 to 0.34. This constraint also limits the systematic error from possiblecharge symmetry violation in the determination of sin^2(theta) from nu-Nscattering experiments.