Nucleon structure functions from relativistic constituent quarks

We investigate deep inelastic lepton scattering from the nucleon within a constituent quark picture, in which the internal structure of the constituent quarks is modeled by meson and diquark dressing. In a covariant framework this structure leads to a breakdown of the factorization necessary for a convolution formulation. We perform our analysis in time-ordered perturbation theory in the infinite momentum frame where factorization of subprocesses is automatic. Numerical results are compared with recent data on valence quark distributions in the proton.