Antibound states and halo formation in the Gamow shell model

Abstract

The open quantum system formulation of the nuclear shell model, the so-called Gamow shell model (GSM), is a multiconfigurational SM that employs a single-particle basis given by the Berggren ensemble consisting of Gamow states and the non-resonant continuum of scattering states. The GSM is of particular importance for weakly bound/unbound nuclear states where both many-body correlations and the coupling to decay channels are essential. In this context, we investigate the role of $\ensuremath{\ell}=0$ antibound (virtual) neutron single-particle states in the shell model description of loosely bound wave functions, such as the ground state wave function of a halo nucleus $^{11}\mathrm{Li}$.