Spontaneous fission half-lives for heavy and super-heavy nuclei from phenomenological models

TL;DR

This paper introduces a phenomenological model based on the effective tunneling barrier to systematically predict spontaneous fission half-lives of heavy and super-heavy nuclei, achieving improved accuracy over previous models.

Contribution

The paper presents a new phenomenological approach using the effective tunneling barrier that better reproduces known SF half-lives and provides reliable predictions for superheavy nuclei.

Findings

The model reproduces 79 known nuclei's SF half-lives with 0.8 deviation on average.

Predicted SF half-lives for superheavy nuclei around N=184 vary from 10 to 160 ms.

Predictions suggest some superheavy nuclei could survive long enough for detection.

Abstract

A phenomenological model is proposed for a systematic description of the spontaneous fission (SF) half-lives $T_{\rm SF}$ of heavy and super-heavy nuclei. Based on the effective tunneling barrier (ETB), the proposed approach reproduces the SF half-lives of 79 known nuclei with an average deviation of 0.8, which is $17\%$ smaller than that of the linear correlation approach recently proposed in [N. S. Moiseev, N. V. Antonenko and G. G. Adamian, Phys. Rev. C 112, 034607 (2025)]. For superheavy nuclei with $45\leqslant N-Z \leqslant 61$, the predicted SF half-lives from these two different phenomenological models are in good agreement with each other. The ETB calculations implies that the $\beta$-decay energy affects the SF half-lives of nuclei far from the $\beta$-stability line. For superheavy nuclei around the magic number $N=184$, the predicted $T_{\rm SF}$ of $^{304}$120 is much shorter than that of $^{298}$Fl. With predicted values of about $10 \sim 160$ ms for $T_{\rm SF}$, the unmeasured SHN $^{293}119 $ could survive for long enough to reach the focal-plane detector in detection systems like the gas-filled recoil separator SHANS in Lanzhou.