SEARCH FOR A NONLOCAL POTENTIAL FROM A LOCAL POTENTIAL OBTAINED WITH ELASTIC-SCATTERING PHASE-SHIFTS OF THE ALGEBRAIC SCATTERING-THEORY

The local energy-dependent potential for the elastic scattering of 16O on 28Si, which was obtained by an inversion procedure from elastic scattering phase shifts of the algebraic scattering theory, is shown to be explainable in terms of a non-local potential. The local and non-local potentials get connected by two different methods: by a Taylor expansion of the non-local potential and by a Wigner representation of this potential within the method of effective equivalent wave numbers. Whereas the method using the Taylor expansion yields a useful non-local potential, the method of effective equivalent wave numbers gives unsatisfactory results.