Probing the structural evolution along the fission path in the superheavy nucleus $^{256}$Sg

TL;DR

This study investigates the structural evolution of the superheavy nucleus $^{256}$Sg along its fission path using multi-dimensional potential-energy surface calculations, revealing the influence of triaxial and hexadecapole deformations on fission barriers.

Contribution

It introduces a detailed multi-dimensional analysis of shape degrees of freedom affecting fission pathways in superheavy nuclei, incorporating microscopic effects.

Findings

Triaxial deformation can facilitate bypassing the first fission barrier.

Shape degrees of freedom influence the fission pathway after the first energy minimum.

Microscopic effects like pairing and Coriolis are relevant in the structural evolution.

Abstract

The evolution of structure property along the fission path in the superheavy nucleus $^{256}$Sg is predicted through the multi-dimensional potential-energy(or Routhian)-surface calculations,in which the phenomenological deformed Woods-Saxon potential is adopted. Calculated nuclear deformations and fission barriers for $^{256}_{106}$Sg$_{150}$ and its neighbors, e.g., $^{258,260}$Sg, $^{254}$Rf and $^{252}$No are presented and compared with other theoretical results. A series of energy maps and curves are provided and used to evaluate the corresponding shape-instability properties, especially in the directions of triaxial $\gamma$ and different hexadecapole deformations (e.g., $\alpha_{40}$, $\alpha_{42}$ and $\alpha_{44}$). It is found that the triaxial deformation may help the nucleus bypass the first fission-barrier of the axial case. After the first minimum in the nuclear energy surface, the fission pathway of the nucleus can be affected by $\gamma$ and hexadecapole deformation degrees of freedom. In addition, microscopic single-particle structure, pairing and Coriolis effects are briefly investigated and discussed.