Assuming that the elastic scattering between heavy ions, at energies just above the Coulomb barrier, is dominated by the physical phenomenon of reflection at the nuclear surface, it is possible to formulate a new model of heavy ion scattering which appears to be able to account both for the energy and angular dependence of the experimental differential cross sections. The model, named the reflective model, is based on suitable modifications of the scattering function for the scattering of charged particles by an impenetrable charged sphere and is an extension to quantum mechanics of a similar classical model previously formulated. In its simpler formulation the reflective model depends on two parameters: the first parameter is the radius of the reflecting region and the second gives a measure of the probability that the reflection phenomenon occurs when the surfaces of two nuclei come in contact. The analysis of the experimental angular distributions indicates that the radius parameter follows the usual law of nuclear radii and that the reflective parameter depends weakly on the energy and on the particular pair of nuclei in collision. The two-parameter version of the model violates the unitarity bound, but the introduction of two additional parameters, which physically control the importance of the diffractive contribution, allows one to avoid this difficulty and to obtain a better agreement with the experimental results. In contrast with the optical model case, the parameters of the reflective model are rather well determined by the analyses of the experimental results, and this seems to provide an indication that they describe some real properties of the interaction between nuclei.

• Received 17 December 1990

DOI:https://doi.org/10.1103/PhysRevC.44.796