VACUUM CONTRIBUTIONS IN A CHIRAL EFFECTIVE LAGRANGIAN FOR NUCLEI

A relativistic hadronic model for nuclear matter and finite nuclei, wh ich incorporates nonlinear chiral symmetry and broken scale invariance , is presented and applied at the one-baryon-loop level to finite nucl ei. The model contains an effective light scalar held that is responsi ble for the midrange nucleon-nucleon attraction and which has anomalou s scaling behavior. One-loop vacuum contributions in this background s calar field at finite density are constrained by low-energy theorems t hat reflect the broken scale invariance of quantum chromodynamics. A m ean-field energy functional for nuclear matter and nuclei is derived t hat contains small powers of the fields and their derivatives, and the validity of this truncation is discussed. Good fits to the bulk prope rties of finite nuclei and single-particle spectra are obtained.