Nonsinglet valence-quark distribution from neutrino-deuterium deep-inelastic scattering

The deep-inelastic scattering reaction ..nu../sub ..mu../N..--> mu../sup -/X has been studied using the deuterium-filled 15-foot bubble chamber at Fermilab. The data have been analyzed under the assumption of isospin invariance to extract x(u/sub V/-d/sub V/) for the proton, where xu/sub V/(x) and xd/sub V/(x) are the valence up- and down-quark momentum distributions, respectively. The results are compared with other data and with different theoretical fits. The ratio ..nu..n/..nu..p as a function of x is also presented.