In-Medium Baryon Interactions and Hypernuclear Structure

We introduce a microscopic and relativistic theory describing free scattering and finite nuclei for the octet baryons in a consistent quantum field theoretical framework based on Dirac-Brueckner theory and nuclear mean-field. In a first quantitative approach - yet still heuristic for dealing with the $\Lambda$ hyperon - the quality of the description of finite (hyper)nuclei based on free meson exchange potentials is competitive with those from purely phenomenological relativistic mean-field calculations. In contrast to the latter our approach has the advantage of having a microscopic link to free interactions and complete control on which classes of diagrams are included. As a complementary way for determining hyperon-hyperon and hyperon-nucleon interactions the use of Hanbury-Brown-Twiss interferometry is discussed.