Dirac Phenomenology and Hyperon-Nucleus Interactions*)

We discuss various aspects of hyperon-nucleus interactions in the relativistic mean field theory. First, characteristics of Λ, Σ and Ξ hypernuclei, as well as multi-strange baryonic objects, are investigated. The spin-orbit splittings and magnetic moments are shown to be very sensitive to the value of the tensor coupling fωY. Second, optical potentials for Λ and Σ scattering off nuclei are developed based on a global nucleon-nucleus Dirac optical potential and SU(3) symmetry. The tensor coupling has a large effect on the predictions for the analyzing power. Third, the Dirac approach is used in the calculations of the non-mesonic decay of Λ hypernuclei. The large discrepancy between the decay rates and data suggests the need for additional meson exchanges.