WIDTHS OF ISOBARIC ANALOG RESONANCES - A MICROSCOPIC APPROACH

A self-consistent particle-phonon coupling model is used to investigat e the properties of the isobaric analog resonance in Bi-208. It is sho wn that quantitative agreement with experimental data for the energy a nd the width can be obtained if the effects of isospin-breaking nuclea r forces are included, in addition to Coulomb force effects. A connect ion between microscopic model predictions and doorway state approaches , which make use of the isovector monopole resonance, is established v ia a phenomenological ansatz for the optical potential.