SLOW PROTON PRODUCTION IN SEMIINCLUSIVE DEEP-INELASTIC SCATTERING ANDTHE PION CLOUD IN THE NUCLEON

The semi-inclusive cross section for producing slow protons in charged current deep inelastic (anti-)neutrino scattering on protons and neut rons is calculated as a function of the Bjorken x and the proton momen tum. The standard hadronization models based upon the colour neutraliz ation mechanism appear to underestimate the rate of slow proton produc tion on hydrogen. The presence of the virtual mesons (pions) in the nu cleon leads to an additional mechanism for proton production, referred to as the spectator process. It is found that at low proton momenta b oth mechanisms compete, whereas the spectator mechanism dominates at v ery small momenta, while the color neutralization mechanism dominates at momenta larger than 1-2 GeV/c. The results of the calculations are compared with the CERN bubble chamber (BEBC) data. The spectator model predicts a sharp increase of the semi-inclusive cross section at smal l x due to the sea quarks in virtual mesons.