On the stability of super-heavy nuclei

TL;DR

This study evaluates the stability and decay properties of super-heavy nuclei using a Fourier shape parametrization, revealing insights into their deformation, fission modes, and agreement with experimental data.

Contribution

It introduces a comprehensive four-dimensional deformation analysis of super-heavy nuclei using a Fourier shape approach, extending understanding of their stability and fission behaviors.

Findings

Good agreement with experimental data where available.

Predicted new fission modes for nuclei beyond Fm.

Analyzed transition from asymmetric to symmetric fission.

Abstract

The potential-energy surfaces of an extended set of heavy and super-heavy even-even nuclei with $92 \le Z \le 126$ and isospins $40 \le N-Z \le 74$ are evaluated within the recently developed Fourier shape parametrization. Ground-state and decay properties are studied for 324 different even-even isotopes in a four-dimensional deformation space, defined by non-axiality, quadrupole, octupole, and hexadecapole degrees of freedom. Nuclear deformation energies are evaluated in the framework of the macroscopic-microscopic approach, with the Lublin-Strasbourg-Drop model and a Yukawa-folded mean-field potential. The evolution of the ground-state equilibrium shape (and possible isomeric, metastable states) is studied as a function of $Z$ and $N$. Alpha-decay $Q$-values and half-lives, as well as fission-barrier heights, are deduced. In order to understand the transition from asymmetric to symmetric fission along the Fm isotopic chain, the properties of all identified fission paths are investigated. Good agreement is found with experimental data wherever available. New interesting features about the population of different fission modes for nuclei beyond Fm are predicted.