Toroidal Super-Heavy Nuclei in Skyrme-Hartree-Fock Approach

TL;DR

This study uses the Skyrme-Hartree-Fock+BCS model to identify conditions under which super-heavy nuclei adopt stable toroidal shapes, revealing a transition from traditional to torus-like nuclear structures depending on Z and A.

Contribution

It demonstrates the existence of energetically favorable toroidal nuclear configurations in super-heavy elements within a self-consistent mean-field framework.

Findings

Toroidal shapes become energetically favorable at high oblate deformations.

The energy difference between toroidal and compact shapes depends on Z and A.

Conditions for global energy minima in toroidal configurations are identified.

Abstract

Within the self-consistent constraint Skyrme-Hartree-Fock+BCS model (SHF+BCS), we found equilibrium toroidal nuclear density distributions in the region of super-heavy elements. For nuclei with a sufficient oblate deformation ($Q_{20}\leq$ -200 b), it becomes energetically favourable to change the genus of nuclear surface from 0 to 1, i.e., to switch the shape from a biconcave disc to a torus. The energy of the toroidal (genus=1) SHF+BCS solution relative to the compact (genus=0) ground state energy is strongly dependent both on the atomic number Z and the mass number A. We discuss the region of Z and A where the toroidal SHF+BCS total energy begins to be a global minimum.