Radiative Parton Model Analysis of Recent Polarized DIS Data

Abstract

An updated next-to-leading order (NLO) QCD analysis of the spin asymmetries A_1^N(x,Q^2) and parton distributions delta f(x,Q^2) in longitudinally polarized deep-inelastic lepton-nucleon scattering is presented within the framework of the radiative parton model taking into account recent experimental results. The theoretical framework and the main features of the radiative parton model analysis are briefly reviewed. The small-x behaviour of the polarized structure function g_1^N(x,Q^2) as well as the shape of the polarized gluon distribution delta g(x,Q^2) are shown to be still hardly constrained by present fixed target data.