Light baryons and their electromagnetic interactions in the covariant   constituent quark model
  We extend the confined covariant constituent quark model that was previously developed by us for mesons to the baryon sector. In our numerical calculation we use the same values for the constituent quark masses and the infrared cutoff as have been previously used in the meson sector. In a first application we describe the static properties of the proton and neutron, and the $\Lambda$-hyperon (magnetic moments and charge radii) and the behavior of the nucleon form factors at low momentum transfers. We discuss in some detail the conservation of gauge invariance of the electromagnetic transition matrix elements in the presence of a nonlocal coupling of the baryons to the three constituent quark fields. 
Thomas Gutsche, Mikhail A. Ivanov, Jurgen G. Korner, Valery E.   Lyubovitskij, Pietro Santorelli
hep-ph