A SIMPLIFIED 3-BODY MODEL FOR LI-11 AND ASSOCIATED LI-9 AND NEUTRON MOMENTUM DISTRIBUTIONS

A simple three-body oscillator cluster shell model is proposed to describe the wave functions of neutron-rich nuclei with a (core + 2n) structure. The model is applied to investigate the Li-11 nucleus. With a few free parameters the model is able to reproduce the experimental r.m.s. matter radius of Li-11, as well as the experimental transverse momentum distribution of the Li-9 nucleus from Li-11 fragmentation on a carbon target, at an energy of 790 MeV/nucleon. The transverse momentum distributions of the neutrons from this reaction have also been calculated without any additional parameters. All geometric parameters of the Li-11 nucleus are also calculated in the framework of the three-body model.