Systematics ofα-decay half-lives around shell closures

Abstract

We present a systematic calculation of $\ensuremath{\alpha}$-decay half-lives of even-even heavy and superheavy nuclei in the framework of the preformed $\ensuremath{\alpha}$ model. The microscopic $\ensuremath{\alpha}$-daughter nuclear interaction potential is calculated by double-folding the density distributions of both $\ensuremath{\alpha}$ and daughter nuclei with a realistic effective Michigan three-Yukawa nucleon-nucleon interaction, and the microscopic Coulomb potential is calculated by folding the charge density distributions of the two interacting nuclei. The half-lives are found to be sensitive to the density dependence of the nucleon-nucleon interaction and the implementation of the Bohr-Sommerfeld quantization condition inherent in the Wentzel-Kramers-Brillouin approach. The $\ensuremath{\alpha}$-decay half-lives obtained agree reasonably well with the available experimental data. Moreover, the study has been extended to the newly observed superheavy nuclei. The interplay of closed-shell effects in $\ensuremath{\alpha}$-decay calculations is investigated. The $\ensuremath{\alpha}$-decay calculations give the closed-shell effects of known spherical magicities, $Z=82$ and $N=126$, and further predict enhanced stabilities at $N=152,162$, and $184$ for $Z=100,108$, and $114$, owing to the stability of parent nuclei against $\ensuremath{\alpha}$ decays. It is worth noting that the aim of this work is not only to reproduce the experimental data better, but also to extend our understanding of $\ensuremath{\alpha}$-decay half-lives around shell closures.