Quasielastic Backscattering And Barrier Distribution For The Weakly Bound Projectile Li-6 On Tb-159

The excitation function for quasielastic scattering of the weakly bound projectile Li-6 on a Tb-159 target, at large backward angle, has been measured at energies around the Coulomb barrier. The corresponding quasielastic barrier distribution has been extracted from the experimental cross sections, both including and excluding the alpha particles produced in the reaction. The quasielastic scattering cross sections, excluding the alpha particles, have been analyzed in the framework of coupled channels calculations. The centroid of the quasielastic barrier distribution, including the alpha particles, is found to shift towards higher energy relative to the centroid of the fusion barrier distribution for the system. This has been attributed to the low alpha-breakup threshold of the nucleus Li-6.