Importance of the non-OPEP N--N force and of the exchange potential for elastic scattering of alpha particles

A previous study is generalized by including the exchange as well as the direct parts of the alpha--nucleus potential generated from a density-dependent effective N--N interaction that acts in both even and odd states. It is found that microscopic calculations can correctly predict the normalization and shape of the alpha--nucleus potential near the interaction radius, that exchange effects cannot be neglected and contribute even to the long-range part of the alpha--nucleus potential, and that the elastic scattering of alpha particles is sensitive to the part of the N--N force which does not contain the one-pion-exchange potential. The microscopic description of this potential is tested by the analysis of elastic scattering of alpha particles at low energies from 90Zr and 208Pb. The matter distributions and cross sections are considered