Searching for high-$K$ isomers in the proton-rich $A\sim80$ mass region

TL;DR

This study uses potential-energy-surface calculations to predict numerous high-$K$ isomers in proton-rich $A ilde{80}$ nuclei, revealing their potential for long-lived states and shape coexistence.

Contribution

It provides the first detailed theoretical prediction of high-$K$ isomers in the $A ilde{80}$ mass region, highlighting their excitation energies and shape characteristics.

Findings

Numerous high-$K$ states are predicted in the $A ilde{80}$ region.

Predicted states include $K^{ extpi}=8^{+}$ and $K^{ extpi}=16^{+}$.

Some high-$K$ states have low excitation energies, suggesting long-lived isomers.

Abstract

Configuration-constrained potential-energy-surface calculations have been performed to investigate the $K$ isomerism in the proton-rich $A\sim80$ mass region. An abundance of high-$K$ states are predicted. These high-$K$ states arise from two and four-quasi-particle excitations, with $K^{\pi}=8^{+}$ and $K^{\pi}=16^{+}$, respectively. Their excitation energies are comparatively low, making them good candidates for long-lived isomers. Since most nuclei under studies are prolate spheroids in their ground states, the oblate shapes of the predicted high-$K$ states may indicate a combination of $K$ isomerism and shape isomerism.