A Comparison of the Parton and Light-cone Analyses of Highly Inelastic Leptonic Processes*

We study the relationship between the parton model and the analysis of light-cone singularities for highly inelastic leptonic processes. For deep inelastic lepton scattering the parton model is found to be a momentum space representation of any model in which free field singularities on the light-cone are dominant. Scaling laws and sum rules derived in one approach are shown to obtain in the other with equivalent assumptions. For massive muon pair production the two approaches are found to differ fundamentally. In the parton model the leading singularity is dominated in the high mass limit by the nonsingular annihilation diagram. The scaling law which is obtained in the parton model is not obtained from a light-cone analysis without additional, seemingly arbitrary assumptions. Massive muon pair production therefore tests the parton model in a region where it is not equivalent to the light-cone approach. Several other processes are studied including one particle inclusive e+ eannihilation and photoproduction muon pairs.