HYPERSPHERICAL 3-BODY CALCULATION FOR NEUTRON DRIP-LINE NUCLEI

The hyperspherical harmonics expansion method is applied to a three-bo dy model of two-neutron halo nuclei. Convergence of the expansion has been ensured. A short-range repulsive part is incorporated in the inte raction between the core and the extra-core neutron, to simulate the P auli principle. Two neutron separation energy, rms radii, correlation factor and halo neutron density distributions have been calculated for Li-11. It is found that the convergence of the two-neutron separation energy is relatively slow, while other quantities reach convergence q uickly.