CAN THE NONRELATIVISTIC QUARK-MODEL BE RECONCILED WITH DEEP-INELASTICSCATTERING RESULTS

We define two quantities, which for high Q(2) tend respectively to Bjo rken's and to Gottfried's sum. We elaborate a nonperturbative evolutio n model for such quantities, showing that at low Q(2) they have the sa me evolution and that at Q(2) similar to 0 they match the nonrelativis tic quark model predictions about the axial charge and about the avera ge quark isospin content of the proton.