Elastic scattering in the 6 , 7 Li + 80 Se systems

Abstract

Elastic-scattering angular distributions for the 6,7Li+80Se systems were measured at center-of-mass energies from below to above the Coulomb barrier, 13 < Ec.m<24 MeV. The experimental elastic-scattering cross sections were analyzed within the framework of the optical model to study the energy dependence of the real and imaginary parts of the nuclear-interaction potential. The main objective was to investigate the threshold anomaly, in those weakly bound systems. The behavior of the calculated potentials as a function of energy indicates that our results are qualitatively consistent with the dispersion relation. The threshold anomaly was observed in the 7Li + 80Se and for the 6Li + 80Se system a breakup threshold anomaly is apparent. An analysis of the absorptive processes, involved in the discussion of the experimental results, was performed using th phenomenological optical potentials that best fit the experimental data.