Charge Distributions of Leading Hadrons from 475 GEV Muon-Nucleus Scattering.

Charged hadrons were observed to emerge from inelastic scattering of muons from nuclear targets--hydrogen, deuterium, carbon, calcium, and lead, at E665 at Fermilab. The mean muon beam energy was 475 GeV/c and the energy transfer in the events is required to be greater than 100 GeV. All accepted charged hadrons must have an fractional energy greater than 0.15. The accepted data are in the Bjorken x range 0.0008-0.25, with the mean Q^2 varying from 0.56 to 126 GeV^2 over that range. Cuts are made on exclusive vector mesons, muon-electron scattering, and bremsstrahlung. E665 was designed to minimize secular and geometric acceptance errors for the different targets. The ratios of numbers of positive to negative leading hadrons increase with increasing x, as expected on the Quark-Parton model. A substantial excess in the ratios positives/negatives are observed from hydrogen compared to deuterium over a wide range of x. No significant differences in charge distribution ratios are seen between deuterium and any of the heavier elements, within statistics --about 2% at lower x. Net charge distributions and correlations of the charges of multiple hadrons in an event are discussed.