Quadrupole and octupole collectivity and cluster structures in neon isotopes

TL;DR

This paper uses a theoretical energy density functional approach to study quadrupole and octupole collectivity, cluster structures, and shape coexistence in neon isotopes, matching experimental data and exploring neutron contributions.

Contribution

It introduces a comprehensive theoretical framework combining energy density functionals, projection techniques, and generator coordinate methods to analyze neon isotopes' structure.

Findings

Good agreement with experimental excitation energies and transition rates.

Cluster configurations significantly influence low-energy states.

Neutron valence shells affect molecular-like cluster bonds.

Abstract

The lowest positive- and negative-parity bands of $^{20}$Ne and neutron-rich even-even Ne isotopes are investigated using a theoretical framework based on energy density functionals. Starting from a self-consistent relativistic Hartree-Bogoliubov calculation of axially-symmetric and reflection-asymmetric deformation energy surfaces, the collective symmetry-conserving states are built using projection techniques and the generator coordinate method. Overall a good agreement with the experimental excitation energies and transition rates is obtained. In particular, the model provides an accurate description of the excitation spectra and transition probabilities in $^{20}$Ne. The contribution of cluster configurations to the low-energy states is discussed, as well as the transitional character of the ground state. The analysis is extended to $^{22}$Ne and the shape-coexisting isotope $^{24}$Ne, and to the drip-line nuclei $^{32}$Ne and $^{34}$Ne. The role of valence neutrons in the formation of molecular-type bonds between clusters is discussed.