Neutron halo in deformed nuclei

TL;DR

This paper investigates neutron halos in deformed nuclei using a self-consistent relativistic theory, revealing how halos can have different shapes from their cores, exemplified by studies on magnesium isotopes.

Contribution

It introduces a fully self-consistent deformed relativistic Hartree Bogoliubov approach to study halo phenomena in deformed nuclei, highlighting shape decoupling effects.

Findings

Halo in $^{44}$Mg has a different shape from its core.

Decoupling of halo orbitals from core deformation is observed.

The theory accurately describes large spatial extensions and deformation effects.

Abstract

Halo phenomena in deformed nuclei are investigated within a deformed relativistic Hartree Bogoliubov (DRHB) theory. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Contributions of the halo, deformation effects, and large spatial extensions of these systems are described in a fully self-consistent way by the DRHB equations in a spherical Woods-Saxon basis with the proper asymptotic behavior at large distance from the nuclear center. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nucleus $^{44}$Mg. The core of this nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the occurence of this decoupling effects are discussed.