Speaker: Mark Paris (T-16)

Spin asymmetries for confined Dirac particles

We employ a simple, exactly solved model of confined Dirac particles to understand spin structure in hadrons. Specifically, we study the Bjorken x (or Nachtmann xi) dependence of the the virtual photon spin asymmetry in deep inelastic scattering of longitudinally polarized electrons from longitudinally polarized protons and neutrons. We use a relativistic potential model of the hadron, treating the constituents as independent massless Dirac particles confined to an infinitely massive force center. The importance of the p-wave components of the Dirac wave function is demonstrated. Comparisons are made to the observed data on protons and neutrons by taking into account the observed flavor dependence of the valence quark distributions.