Systematic study of the half-lives of nuclear bound-state ${\beta }^{-}$ decay

Abstract

Nuclear bound-state ${\beta }^{-}$ decay (${\beta }_{\text{b}}$ decay) is a novel weak-interaction process that becomes possible when atoms are highly ionized, such as in stellar environments or heavy-ion storage rings. In this work we present a systematic theoretical calculations for the ${\beta }_{\text{b}}$-decay half-lives of interesting candidates for the first time, where both allowed Gamow-Teller transitions and first-forbidden transitions are taken into account by the microscopic projected shell model, and the lepton phase space is calculated by the Takahashi-Yokoi model. We analyzed the structure informations for hundreds of nuclei near the $\beta$-stability line, and select 16 interesting candidates belonging to two categories, i.e., nuclei with negative $Q$ values and positive $Q$ values in neutral atoms respectively. Among these candidates, we recommend ${}^{243}{\mathrm{Am}}^{95+}$, ${}^{194}{\mathrm{Os}}^{76+}$, ${}^{227}{\mathrm{Ac}}^{89+}$, ${}^{228}{\mathrm{Ra}}^{88+}$, ${}^{241}{\mathrm{Pu}}^{94+}$, ${}^{247}{\mathrm{Cm}}^{96+}$ and ${}^{250}{\mathrm{Cm}}^{96+}$ as promising ones for future studies of storage-ring experiments because their ${\beta }_{\text{b}}$-decay half-lives are predicted to be much shorter than the half-lives in neutral atoms. These findings provide essential nuclear inputs for astrophysical models and identify specific candidates where experimental verification would be most valuable.