Nucleon Form Factors in the Covariant Diquark-Quark Model

Abstract

The nucleon is described as a bound state of a quark and an extended diquark. Hereby the notion ``diquark'' refers to the modelling of separable correlations in the two-quark Green's functions. Binding of quarks and diquarks takes place via an exchange interaction and is therefore related to the Pauli principle for three-quark states. Fully Poincare covariant nucleon amplitudes are calculated for free constituent propagators as well as for dressed propagators which parameterise confinement. The corresponding results for space-like form factors differ quantitatively but not qualitatively for various ansätze for the propagators. These results do not allow to draw definite conclusions on the permissibility of different dressing functions. Results for kaon photoproduction, on the other hand, exclude a whole class of constituent propagators.

8 pages, 4 figures; to appear in the proceedings of the workshop on Lepton scattering, Hadrons and QCD, Adelaide, March 26 to April 6, 2001