Nature of isomerism in exotic sulfur isotopes

TL;DR

This paper investigates the origin of hindered E2 decay in sulfur isotope 44S, revealing it as a high-K isomer with significant triaxiality through shell model analysis.

Contribution

It introduces a novel shell model analysis demonstrating the high-K isomer nature of the 4+ state in 44S, highlighting its unique triaxial configuration.

Findings

The 4+_1 state in 44S is a K=4 isomer dominated by two-quasiparticle configuration.

The 4+_1 state exhibits significant triaxiality.

The study clarifies the origin of hindered E2 decay in 44S.

Abstract

We clarify the origin of the anomalously hindered $E2$ decay from the $4^+_1$ level in $^{44}$S by performing a novel many-body analysis in the shell model. Within a unified picture about the occurrence of isomerism in neutron-rich sulfur isotopes, the $4^+_1$ state is demonstrated to be a $K=4$ isomer dominated by the two-quasiparticle configuration $\nu\Omega^{\pi}=1/2^-\otimes\nu\Omega^{\pi}=7/2^-$. The $4^+_1$ state in $^{44}$S is a new type of high-$K$ isomer which has significant triaxiality.