Baryon Structure in a Covariant Diquark-Quark Model
  The baryon structure is investigated in a covariant diquark-quark model. In this approach baryons emerge as relativistic bound states of a constituent quark and a $0^{+}$ or $1^{+}$ diquark. After solving the Bethe-Salpeter Equation for the scalar diquark quark system in ladder approximation we couple various external currents to the constituents of the baryon to probe its internal structure. The quark and the diquarks are assumed to be confined which is implemented by suitable choices for the propagators. This leads to nontrivial vertex functions between the constituents and the external current. Baryonic matrix elements are then evaluated to extract observable formfactors. 
G. Hellstern, R. Ba\"urle, U. Z\"uckert, R. Alkofer, H. Reinhardt