DEEP-INELASTIC SCATTERING AND FINAL-STATE INTERACTION IN AN EXACTLY SOLVABLE RELATIVISTIC MODEL

In the theory of deep inelastic scattering the final state interaction between the struck quark and the remnants of the target is usually as sumed to be negligible in the Bjorken limit. This assumption, still aw aiting a full validation within nonperturbative QCD, is investigated i n a model composed of mio relativistic particles, interacting via a re lativistic harmonic oscillator potential, within light-cone Hamiltonia n dynamics. An electromagnetic current operator whose matrix elements behave properly under Poincare transformations is adopted. It is shown that (i) the parton model is recovered, once the standard parton mode l assumptions are adopted, and (ii) when relativistic, interacting eig enfunctions are exactly taken into account for both the initial and fi nal states, the values of the structure functions, averaged over small , but finite intervals of the Bjorken variable x, coincide with the re sults of the parton model in the Bjorken limit. [S0556-2813(98)00405-1 ].