Optical Model in the Interior of the Nucleus. II

Abstract

Factors which influence the relative contribution of the interior and the surface of the nucleus to matrix elements for direct interactions involving nucleons in the entrance and exit channels are studied quantitatively. Purely optical-model effects causing localization of the reaction are phase averaging, which tends to de-emphasize the interior at all energies, and focusing which emphasizes the interior at low energies and the surface at higher energies. It is shown that phase averaging does not make the central contribution negligible at any energy. The foci in the optical-model wave functions have large effects on angular distributions. Density dependence of the two-body force for reactions which proceed by a two-body collision mechanism can be identified from angular distributions and from the energy dependence of backward cross sections which are particularly sensitive to the foci.