# Assessing theoretical uncertainties in fission barriers of superheavy nuclei

## TL;DR

This paper systematically investigates theoretical uncertainties in predicting fission barrier heights of superheavy nuclei using covariant density functional theory, highlighting large uncertainties and their implications for nuclear stability predictions.

## Contribution

It provides a comprehensive analysis of systematic and statistical uncertainties in fission barrier predictions across different models and benchmarks them with experimental data.

## Key findings

- Systematic uncertainties are larger than statistical ones.
- Uncertainties increase when moving away from benchmark regions.
- Differences in barrier heights can reach 5-6 MeV, affecting fission half-life estimates.

## Abstract

Theoretical uncertainties in the predictions of inner fission barrier heights in superheavy elements have been investigated in a systematic way for a set of state-of-the-art covariant energy density functionals which represent major classes of the functionals used in covariant density functional theory. They differ in basic model assumptions and fitting protocols. Both systematic and statistical uncertainties have been quantified where the former turn out to be larger. Systematic uncertainties are substantial in superheavy elements and their behavior as a function of proton and neutron numbers contains a large random component. The benchmarking of the functionals to the experimental data on fission barriers in the actinides allows to reduce the systematic theoretical uncertainties for the inner fission barriers of unknown superheavy elements. However, even then they on average increase on moving away from the region where benchmarking has been performed. In addition, a comparison with the results of non-relativistic approaches is performed in order to define full systematic theoretical uncertainties over the state-of-the-art models. Even for the models benchmarked in the actinides, the difference in the inner fission barrier height of some superheavy elements reaches $5-6$ MeV. This uncertainty in the fission barrier heights will translate into huge (many tens of the orders of magnitude) uncertainties in the spontaneous fission half-lives.