Coulomb-nuclear interference at sub-Coulomb energies

The Coulomb-nuclear interference pattern in the low-energy heavy-ion excitation of nuclei near closed-shells can be used to investigate the nuclear mass density at large distances, the nature of the effective transition operator and the presence of higher-order direct processes. Semimicroscopic single-folding calculations are compared to low-energy data for ¹⁸O excitation by ²⁰⁸Pb. A strong effect of two-step transfer reactions is predicted in the sub-Coulomb excitation of ¹⁷O by ²⁰⁸Pb.