Models for the polarized parton distributions of the nucleon - art. no. 094005

Polarized deep inelastic scattering (DIS) data are analyzed in leading and next-to-leading order of QCD within the common "standard" scenario of polar ized parton distributions with a flavor-symmetric light sea (antiqualk) dis tribution delta(q) over bar, and a completely SU(3)(f) broken "valence" sce nario with totally flavor-asymmetric light sea densities (delta(u) over bar not equal delta(d) over bar not equal delta(s) over bar). The latter flavo r-broken light sea distributions are modeled with the help of a Pauli-block ing ansatz at the low radiative or dynamical input scales of mu (2)(LO(NLO) ) = 0.26 (0.40) GeV2 which complies with predictions of the chiral quarh;-s oliton model and expectations based on the statistical parton model as well as with the corresponding, well established, flavor-broken unpolarized sea ((d) over bar><(<mu>)over bar>). Present semi-inclusive DIS data cannot ye t uniquely discriminate between those two flavor-symmetric and flavor-broke n polarized light sea scenarios.