Inelastic Lepton-Nucleon Scattering and Lepton Pair Production in the Relativistic Quark-Parton Model

We discuss the interaction of hadrons with leptons in the limit of large momentum transfer. A special parton model will be used for the hadrons in which the partons are identified with quarks. The relativistic quark model with which we interpret recent observations is formulated as follows: (1) The baryons are composed of three valence quarks and a core of an indefinite number of quark-antiquark pairs. (2) The lepton "sees" the nucleon in the limit of large momenta in the c.m. frame as an assembly of freely moving constitutents with point charges. (3) The scattering of the valence quarks is interpreted as the nondiffractive component, the scattering of the core is interpreted as the diffractive component of the cross section. (4) The nondiffractive scattering is assumed to be mediated by suitable meson exchanges, and this assumption determines the momentum distribution of the valence quarks. The ($q\overline{q}$) pairs in the core are assumed to be distributed statistically in the available phase space. (5) It will be necessary to include "gluons" among the constituents of the nucleon. They are supposed to be the uncharged quanta of the force field between quarks and are assumed to be distributed statistically over the momentum space. There is only one constant adjustable in this model, which is the ratio of gluons to core pairs. All other constants are fixed by simple considerations. This model is used to calculate the deep-inelastic scattering of electrons by protons and neutrons and its dependence on the relative spin orientations, the inelastic scattering of neutrinos by nucleons, and the creation of massive muon pairs by proton-proton collisions. After adjusting the open constant to the data of electron-proton scattering, the theory predicts unambiguously the other results. They are in reasonably good agreement with the observations as far as they are known.