Deformation and its influence on $K$ isomerism in neutron-rich Hf nuclei

TL;DR

This paper explores how nuclear deformation affects the existence of long-lived $K$ isomers in neutron-rich Hf isotopes, using potential-energy surface calculations to support the potential for these isomers to be exceptionally long-lived.

Contribution

It provides the first detailed theoretical analysis of deformation effects on $K$ isomer stability in neutron-rich Hf isotopes around N=116.

Findings

Multi-quasiparticle states remain robust against triaxial distortion.

Long-lived $K$ isomers are supported by the calculations.

Results align with available experimental data.

Abstract

We investigate the influence of deformation on the possible occurrence of long-lived $K$ isomers in Hf isotopes around N=116, using configuration-constrained calculations of potential-energy surfaces. Despite having reduced shape elongation, the multi-quasiparticle states in $^{186,188}$Hf remain moderately robust against triaxial distortion, supporting the long expected occurrence of exceptionally long-lived isomers. The calculations are compared with available experimental data.