Reaction mechanisms in the scattering of 8 Li on 208 Pb around the Coulomb barrier

Abstract

We present an analysis of the reaction 8 Li + 208 Pb , which has been recently measured at energies around the Coulomb barrier. The study is focused on the elastic and one-neutron removal channels. The elastic angular distribution has been analyzed by means of the optical model and coupled-channels method. The measured 7 Li yield has been assumed to come from the one-neutron transfer reaction 208 Pb ( 8 Li ,

7 Li ) 209 Pb and the breakup reaction 8 Li + 208 Pb → n + 7 Li + 208 Pb . For the former, an analysis in terms of the distorted wave Born approximation and coupled-channels Born approximation (CCBA) methods has been performed. For the breakup reaction, a generalization of the CCBA method has been used, in which the final states are described as n + 208 Pb continuum states. Transfer and breakup are then treated consistently. The summed angular distribution for the two processes reproduces the shape and absolute magnitude of the measured 7 Li distribution. We conclude that most of the measured 7 Li yield comes from the one-neutron transfer channel. We also show that the elastic scattering is notably affected by the strong coupling to transfer channels.