Electromagnetic Transitions of Hyperons in a Relativistic Quark Model

The Lorentz-covariant Bethe-Salpeter model developed by the Bonn group is used to calculate the electromagnetic form factors of the ground-state hyperons and the helicity amplitudes of the hyperon resonances. The computed magnetic moments of the ground- state hyperons agree well with the experimental values and the magnetic form factors exhibit a dipole Q2-dependence. The photo-amplitude of the Λ(1405) is badly reproduced, which hints at the special structure of this resonance.