Forward produced hadrons in μp and μd scattering and investigation of the charge structure of the nucleon

Final data measured with the EMC forward spectrometer are presented on the production of forward charged hadrons in μp and μd scattering at incident beam energies between 100 and 280 GeV. The large statistic of 373 000 events allows a study of the semi-inclusive hadron production as a function ofz,p T 2 and 〈p T 2 〉 in smallQ2,x Bj andW bins. Charge multiplicity ratios and differences as a function ofz andx Bj are given forp, d andn-targets. From the differences of charge multiplicities the ratio of the valence quark distributions of the protond v (x)/u v (x) is determined for the first time in charged lepton scattering. The Gronau et al. sum rule is tested, the measured sum being 0.31±0.06 stat. ±0.05 syst., compared with the theoretical expectation of 2/7≈0.286. The measured sum corresponds to an absolute value of the ratio of thed andu quark charge of 0.44±0.10 stat.±0.08 syst.