Octupole deformation in the ground states of even-even $Z\sim 96, N\sim 196$ actinides and superheavy nuclei

TL;DR

This study systematically investigates octupole deformation in actinides and superheavy nuclei using covariant density functional theory, identifying regions of deformation and quantifying uncertainties across different models.

Contribution

It provides a detailed analysis of octupole deformation in nuclei around Z~96, N~196, and compares predictions across multiple theoretical frameworks, highlighting model-dependent differences.

Findings

Octupole deformation exists near Z~96, N~196 in covariant DFT.

Uncertainties increase for superheavy nuclei with Z~120, N~190.

Different models predict varying regions of octupole deformation.

Abstract

A systematic search for axial octupole deformation in the actinides and superheavy nuclei with proton numbers $Z=88-126$ and neutron numbers from two-proton drip line up to $N=210$ has been performed in covariant density functional theory (DFT) using four state-of-the-art covariant energy density functionals representing different model classes. The nuclei in the $Z\sim 96, N\sim 196$ region of octupole deformation have been investigated in detail and the systematic uncertainties in the description of their observables have been quantified. Similar region of octupole deformation exists also in Skyrme DFT and microscopic+macroscopic approach but it is centered at somewhat different particle numbers. Theoretical uncertainties in the predictions of the regions of octupole deformation are increasing on going to superheavy nuclei with $Z\sim 120, N\sim 190$. There are no octupole deformed nuclei for $Z=112-126$ in covariant DFT calculations. This agrees with Skyrme DFT calculations, but disagrees with Gogny DFT and microscopic+macroscopic calculations which predict extended $Z\sim 120, N\sim 190$ region of octupole deformation.