Semiclassical analysis of the scattering of 16O by 28Si

Semiclassical analysis of the optical potentials which fit the recent Stony Brook-BNL ¹⁶O + ²⁸Si scattering data, shows that the scattering mechanism of these potentials at backward angles is essentially the same. Neither the reflection from the sharp surface of the surface transparent potential used by Dehnhard and Shkolnik, Golin and Kahana, nor the modified form factor in the potential used by Lee and Chan is essential to fit the angular distribution. Based on the uniform approximation, we derive analytic formula to understand the angular distribution at backward angles and to understand the oscillatory structure in the 180° excitation functions.