DEEP-INELASTIC SCATTERING AND NONRELATIVISTIC QUARK-MODEL - ISOTRIPLET SECTOR

We try to reconcile the nonrelativistic quark model predictions with d eep inelastic experimental and theoretical results about the first mom ents of the leading twist contributions to the isotriplet unpolarized and polarized nucleon structure functions (which, by the way, in the l imit of large Q(2) tend respectively to the Gottfried sum and to the B jorken sum). To this end we propose a nonperturbative evolution model for such moments, showing that for Q(2) less than 4 GeV2 they have the same evolution and that, starting from deep inelastic results at larg e Q(2), at very small Q(2) the moments match the nonrelativistic quark model predictions.