TANGENTIAL VELOCITY AND HALO EFFECTS IN THE 9Li+p AND 11Li+p ELASTIC SCATTERINGS

Abstract

We present the Coulomb-modified eikonal model formalism based on a hyperbolic trajectory by using a tangential velocity at the distance of closest approach. By assuming that 11 Li has a halo structure of two weakly bound neutrons around the 9 Li core, we take the total nuclear optical potential as a sum of the core and the two halo neutrons. The theoretical calculations for the elastic scattering of 9 Li + p and 11 Li + p at E lab /A=60 and 62 MeV, respectively are in good agreements with the observed data. It is found that the break-up effect of halo neutrons and the tangential velocity at the distance of closest approach are both important to understand the elastic cross sections of 11 Li + p system at E lab /A=62 MeV .