NN CORE INTERACTIONS AND DIFFERENTIAL CROSS-SECTIONS FROM ONE GLUON EXCHANGE

We derive nonstrange baryon-baryon scattering amplitudes in the nonrel ativistic quark model using the ''quark Born diagram'' formalism. This approach describes the scattering as a single interaction, here the o ne-gluon-exchange (OGE) spin-spin term followed by constituent interch ange, with external nonrelativistic baryon wave functions attached to the scattering diagrams to incorporate higher-twist wave-function effe cts. The short-range repulsive core in the NN interaction has previous ly been attributed to this spin-spin interaction in the literature; we find that these perturbative constituent-interchange diagrams do inde ed predict repulsive interactions in all I, S channels of the nucleon- nucleon system, and we compare our results for the equivalent short-ra nge potentials to the core potentials found by other authors using non perturbative methods. We also apply our perturbative techniques to the NDELTA and DELTADELTA systems: Some DELTADELTA channels are found to have attractive core potentials and may accommodate ''molecular'' boun d states near threshold. Finally we use our Born formalism to calculat e the NN differential cross section, which we compare with experimenta l results for unpolarized proton-proton elastic scattering. We find th at several familiar features of the experimental differential cross se ction are reproduced by our Born-order result.