Global optical model potentials for symmetrical lithium systems: 6Li+ 6Li, 7Li+ 7Li at Elab = 5–40 MeV

Abstract

Angular distributions of 6Li+ 6Li elastic scattering were measured for E lab = 5–40 MeV. An optical model analysis of these data together with older data of 7Li+ 7Li elastic scattering taken at E lab = 8–17 MeV was performed with the aim to search for a “global” OM potential which describes elastic scattering in both LiLi systems in a broad energy range. Both surface and volume absorbing potentials can be found which fulfill this requirement if a linear energy dependence is assumed of the depths of the real as well as the imaginary potential. These depths, if fitted to individual angular distributions, are found to vary in a correlated manner with the beam energy. This is taken as indication of strong coupling between elastic, inelastic, and reaction channels. This is corroborated by the existence of resonances in reaction channels at these energies where the potential depths are most pronouncedly changing.