THE THRESHOLD ANOMALY AND INELASTIC-SCATTERING

The threshold anomaly exhibited in low-energy, heavy-ion reactions is described using O-16+Pb-208 as an example. Variations in the elastic-scattering potential, U, are found to obey a dispersion relation, and the overall features are well reproduced by coupled reaction-channel calculations. New data are presented on the behaviour near threshold of an inelastic scattering channel. The DWBA transition potential exhibits a strong threshold anomaly, which differs in several respects from that of U. Angular distributions could be fitted only be introducing a strong reorientation term.