Evolution of Surface Deformations of Weakly-Bound Nuclei in the Continuum

TL;DR

This paper investigates the surface deformations and exotic structures of weakly-bound nuclei using a coordinate-space Skyrme Hartree-Fock-Bogoliubov approach, revealing core-halo decoupling phenomena and the role of the continuum.

Contribution

It introduces a detailed analysis of core-halo decoupling and exotic surface structures in weakly-bound nuclei within a coordinate-space framework, highlighting the continuum's role.

Findings

Discovery of an 'egg'-like core-halo structure in $^{38}$Ne.

Reduced halo probability in heavy nuclei due to level density effects.

Possible deformed halos in medium-mass nuclei like $^{110}$Ge.

Abstract

We study weakly-bound deformed nuclei based on the coordinate-space Skyrme Hartree-Fock-Bogoliubov approach, in which a large box is employed for treating the continuum and surface diffuseness. Approaching the limit of core-halo deformation decoupling, calculations found an exotic "egg"-like structure consisting of a spherical core plus a prolate halo in $^{38}$Ne, in which the resonant continuum plays an essential role. Generally the halo probability and the decoupling effect in heavy nuclei are reduced compared to light nuclei, due to denser level densities around Fermi surfaces. However, deformed halos in medium-mass nuclei are possible with sparse levels of negative parity, for example, in $^{110}$Ge. The surface deformations of pairing density distributions are also influenced by the decoupling effect and are sensitive to the effective pairing Hamiltonian.