Summary of Physics Prospects for Polarized Nucleon-Nucleon Scattering at HERA-N

Abstract

The physics scope of polarized nucleon-nucleon collisions originating from an internal polarized target in the HERA proton beam is summarized. Based on 240 pb^{-1} integrated luminosity at 40 GeV c.m. energy, statistical sensitivities are given over a wide (x_F, p_T)-range for a variety of inclusive and exclusive final states. By measuring single spin asymmetries unique information can be obtained on higher twist contributions and their p_T-dependence. From double spin asymmetries in both photon and J/psi production it appears possible to measure the polarized gluon distribution in the range 0.1 < x_{gluon} < 0.4 with a good statistical accuracy. Drell-Yan pair production asymmetries in doubly longitudinal mode, measurable in the mass range 3-10 GeV, allow discrimination between different parametrizations of the polarized light sea quark distributions. In doubly transverse mode access to the quark transversity distribution might become possible. Statistically significant results can be expected in the elastic channel.