PROBLEMS WITH INITIAL-STATE AND FINAL-STATE INTERACTIONS IN DEEP-INELASTIC SCATTERING

Although there exists a vast literature devoted to the theory of deep- inelastic scattering, the restrictions imposed on the (electromagnetic or weak) current operator by its commutation relations with the repre sentation operators of the Poincare group and locality have not been c onsidered. We argue that there is a problem with the current operator, leading to the standard parton-model results, satisfying these restri ctions. At the same time, there exist models where the correct commuta tion relations and locality are satisfied but the initial-and final-st ate interactions of the struck quark with the remnants of the target c annot be neglected even in the Bjorken limit.