FINITE NUCLEI IN RELATIVISTIC MODELS WITH A LIGHT CHIRAL SCALAR MESON

Relativistic chiral models with a light scalar meson appear to provide an economical marriage of successful relativistic mean-field theories and chiral symmetry. The scalar meson serves as both the chiral partn er of the pion and the mediator of the intermediate-range nucleon-nucl eon (NN) attraction. However, while some of these models can reproduce the empirical nuclear matter saturation point, they fail to reproduce observed properties of finite nuclei, such as spin-orbit splittings, shell structure, charge densities, and surface energetics. These defic iencies imply that this realization of chiral symmetry is incorrect. A n alternative scenario, which features a heavy chiral scalar and dynam ical generation of the NN attraction, is discussed.