Nature of isomerism in exotic sulfur isotopes

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.

Comments: 5 pages, 2 figures