# Superheavy nuclei in microscopic collective Hamiltonian approach: the impact of beyond mean field correlations on the ground state and fission properties

## TL;DR

This study investigates how beyond mean field correlations influence the ground state and fission properties of superheavy nuclei, revealing their significant impact on shell closures, collectivity, and fission barrier heights using a covariant density functional theory approach.

## Contribution

It introduces a five-dimensional collective Hamiltonian based on covariant density functional theory to analyze beyond mean field effects on superheavy nuclei, highlighting their impact on shell closures and fission barriers.

## Key findings

- Dynamical correlations reduce the impact of Z=120 shell closure.
- They induce collectivity in Z=120 nuclei that are spherical at mean field level.
- Significant impact on inner fission barrier heights of superheavy nuclei.

## Abstract

The impact of beyond mean field effects on the ground state and fission properties of superheavy nuclei has been investigated in a five-dimensional collective Hamiltonian based on covariant density functional theory. The inclusion of dynamical correlations reduces the impact of the $Z=120$ shell closure and induces substantial collectivity for the majority of the $Z=120$ nuclei which otherwise are spherical at the mean field level (as seen in the calculations with the PC-PK1 functional). Thus, they lead to a substantial convergence of the predictions of the functionals DD-PC1 and PC-PK1 which are different at the mean field level. On the contrary, the predictions of these two functionals remain distinctly different for the $N=184$ nuclei even when dynamical correlations are included. These nuclei are mostly spherical (oblate) in the calculations with PC-PK1 (DD-PC1). Our calculations for the first time reveal significant impact of dynamical correlations on the heights of inner fission barriers of superheavy nuclei with soft potential energy surfaces, the minimum of which at the mean field level is located at spherical shape. These correlations affect the fission barriers of the nuclei, which are deformed in the ground state at the mean field level, to a lesser degree.