Interaction spatial barrier distributions for the proton-halo system 8B+58Ni

Abstract

Radial barrier distributions for the proton-halo system 8B+58Ni are obtained by the use of Woods-Saxon polarization potentials calculated from a fit to elastic scattering angular distribution data. The strength, diffuseness and reduced radii of the polarization potentials, besides fitting the data, are such that reproduce the barrier height and position as extracted from a Wong's fit to the universal behavior of reduced interaction cross sections for halo systems. It is found that, for the proton-halo system 8B+58Ni, the interaction barrier height VI and the interaction barrier radius RI result correspondingly lower and larger than the Coulomb nominal barrier height VB and barrier position RB as expected from Barrier Penetration Models and double folding density dependent interactions such as the São Paulo Potential. It is also shown that, the determined energy dependent polarization potentials, besides satisfying the dispersion relation, present a behavior consistent with the Breakup Threshold Anomaly. Keywords. Nuclear Reactions, weakly bound nuclei, threshold anomaly.