MICROSCOPIC DESCRIPTION OF THE GIANT ELECTRIC-DIPOLE RESONANCE IN MAGIC NUCLEI

An extension of the RPA approach to include both 1p1h x phonon configu rations and the single-particle continuum in a unified framework has b een done using the consistent Green-function formalism. The microscopi c calculations of the giant E1 resonance in Ca-40, 48Ca and Pb-208 hav e been performed in the 1p1h + 2p2h + continuum approximation develope d here. A reasonable agreement with experiment, including a descriptio n of the widths, has been obtained. We underestimate the experimental width values by 14% for Ca-40, 11% for 48Ca and 4% for Pb-208.