DIRAC PHENOMENOLOGY AND HYPERON-NUCLEUS INTERACTIONS

We discuss various aspects of hyperon-nucleus interactions in the rela tivistic mean field theory. First, characteristics of Lambda, Sigma an d Xi hypernuclei, as well as multi-strange baryonic objects, are inves tigated. The spin-orbit splittings and magnetic moments are shown to b e very sensitive to the value of the tenser coupling f(omega Y). Secon d, optical potentials for Lambda and Sigma scattering off nuclei are d eveloped based on a global nucleon-nucleus Dirac optical potential and SU(3) symmetry. The tenser coupling has a large effect on the predict ions for the analyzing power. Third, the Dirac approach is used in the calculations of the non-mesonic decay of Lambda hypernuclei. The larg e discrepancy between the decay rates and data suggests the need for a dditional meson exchanges.