Models for the polarized parton distributions of the nucleon
Models for the polarized parton distributions of the nucleon
Polarized deep inelastic scattering (DIS) data are analyzed in leading and next-to-leading order of QCD within the common ``standard'' scenario of polarized parton distributions with a flavor-symmetric light sea (antiquark) distribution $\ensuremath{\delta}\overline{q},$ and a completely ${\mathrm{SU}(3)}_{f}$ broken ``valence'' scenario with totally flavor-asymmetric light sea densities $(\ensuremath{\delta}\ifmmode \bar{u}\else \={u}\fi{}\ensuremath{\ne}\ensuremath{\delta}\overline{d}\ensuremath{\ne}\ensuremath{\delta}\overline{s}).$ The latter …