Deformed relativistic Hartree Bogoliubov theory in continuum

TL;DR

This paper develops a deformed relativistic Hartree Bogoliubov theory in continuum to accurately describe exotic, weakly-bound nuclei with large spatial extensions, including potential neutron halos, by solving equations in a Woods-Saxon basis.

Contribution

It introduces a formalism for deformed RHB theory in continuum using a Woods-Saxon basis, enabling proper treatment of continuum states and large spatial distributions in exotic nuclei.

Findings

Successfully applied to 20Mg and 42Mg nuclei.

Analyzed conditions for neutron halo formation in deformed nuclei.

Explored the impact of deformation on halo shape.

Abstract

A deformed relativistic Hartree Bogoliubov (RHB) theory in continuum is developed aiming at a proper description of exotic nuclei, particularly those with a large spatial extension. In order to give an adequate consideration of both the contribution of the continuum and the large spatial distribution in exotic nuclei, the deformed RHB equations are solved in a Woods-Saxon (WS) basis in which the radial wave functions have a proper asymptotic behavior at large distance from the nuclear center. This is crucial for the proper description of a possible halo. The formalism of deformed RHB theory in continuum is presented. A stable nucleus, 20Mg and a weakly-bound nucleus, 42Mg, are taken as examples to present numerical details and to carry out necessary numerical checks. In addition, the ground state properties of even-even magnesium isotopes are investigated. The generic conditions of the formation of a halo in weakly bound deformed systems and the shape of the halo in deformed nuclei are discussed. We show that the existence and the deformation of a possible neutron halo depend essentially on the quantum numbers of the main components of the single particle orbitals in the vicinity of the Fermi surface.