Role of triaxiality in deformed halo nuclei

TL;DR

This paper investigates how non-axially symmetric (triaxial) nuclear deformations influence the formation and extent of halo structures in neutron-rich nuclei, expanding understanding beyond previous axially symmetric models.

Contribution

It introduces the consideration of triaxial deformation effects on halo nuclei, showing how $ ext{Ω}$ quantum number mixing can lead to halo formation even without axial symmetry.

Findings

Triaxial deformation can induce halo structures in nuclei where axially symmetric models predict none.

The area of halo nuclei may be extended due to triaxial effects.

Halo formation is influenced by the mixing of angular momentum components in triaxial shapes.

Abstract

It is known that nuclear deformation plays an important role in inducing the halo structure in neutron-rich nuclei by mixing several angular momentum components. While previous theoretical studies on this problem in the literature assume axially symmetric deformation, we here consider non-axially symmetric deformations. With triaxial deformation, the $\Omega$ quantum number is admixed in a single-particle wave function, where $\Omega$ is the projection of the single-particle angular momentum on the symmetric axis, and the halo structure may arise even when it is absent with the axially symmetric deformation. In this way, the area of halo nuclei may be extended when triaxial deformation is considered. We demonstrate this idea using a deformed Woods-Saxon potential for nuclei with neutron number N=13 and 43.