A microscopic hyper-spherical model of two-neutron halo nuclei

We have developed a microscopic cluster model of light two neutron halo nuclei that incorporates the few-body asymptotics in full extent. The wavefunction of the system consists of a core and two valence neutrons. The core is given in terms of correlated Gaussians. The three-body dynamics between the core and valence neutrons is taken into account by means of the hyper-spherical functions containing an exponentially decaying hyper-radial part. To avoid the spurious motion of the center of mass, Jacobi coordinates are used for the entire system.;In the present work, the model is applied to the lightest two-neutron halo nucleus, 6He. The central Minnesota nucleon-nucleon interaction with and without a spin-orbit addition is used to bind the nucleus. The results are compared to those obtained in other models and to experimental data. Basic structural observables, such as binding relative to 4He, radii and one-body densities are in agreement with other models. The microscopic description of the core allows us to test the efficiency of Pauli projection techniques employed in the few-body models. We demonstrate that proper antisymmetrization is crucial to bind 6He against three-body break-up. Overlap functions between 6He and 4He have been extracted with the aim of reaction calculations involving 6He. In particular, two-neutron transfer reaction p(6He, 4He)t at 25MeV/A is studied.