Quasielastic scattering of $^{11}$Li and $^{12}$Be on $^{12}$C

Abstract : The quasielastic Li-11,Be-12 + C-12 scattering at E/A similar or equal to 60 MeV has been studied by adding a fitted polarisation potential to the folding model potential derived from Li-9,Be-12 -C-12 and neutron-C-12 phenomenological optical potentials. For Li-11 + C-12 scattering we have required that our potentials reproduce simultaneously quasielastic data, reaction and break-up cross sections with a polarisation potential satisfying the global properties derived theoretically by several authors. We have shown that an overall agreement is achieved if the Li-11 wave function has a large (2s)(2) two-neutron component and only in this case, For a Be-12 projectile we were able to reproduce the quasielastic data with reasonable reaction cross section and polarisation potential. However, when a similar analysis has been performed for Li-11 + Si-28 scattering at E/A = 29 MeV we have failed to explain the data.