Nucleons in the Covariant Quark-Diquark Model

Abstract

We introduce diquarks as separable correlations in the two-quark Green's function to facilitate the description of baryons as relativistic three-quark bound states. These states then emerge as solutions of Bethe-Salpeter equations for quarks and diquarks that interact via quark exchange. Approximating quark and diquark propagators by the corresponding free ones, we calculate nucleon static properties and form factors. For the description of production processes off the nucleon, we consider various dressing functions for the propagators to remove unphysical thresholds. Results for kaon photoproduction, $\gamma p\to K\Lambda$, and associated strangeness production, $pp\to pK\Lambda$, allow us to draw conclusions on the permissibility of different dressing functions.