Nuclear level densities in the relativistic Hartree-Bogoliubov plus combinatorial framework

TL;DR

This paper evaluates the relativistic Hartree-Bogoliubov plus combinatorial model's effectiveness in predicting nuclear level densities, comparing results across different functionals and with experimental data.

Contribution

It systematically assesses the model's performance and the impact of various functionals, pairing, and deformation on nuclear level density predictions.

Findings

The model accurately reproduces experimental level densities.

It matches neutron resonance spacings as well as leading global models.

Differences in effective mass among functionals significantly affect results.

Abstract

A systematic study of nuclear level densities has been carried out within the relativistic Hartree-Bogoliubov plus combinatorial framework. Calculations were performed for even-even nuclei with available experimental data, based on the relativistic energy density functionals DD-ME2, DD-PC1, and PC-PK1. The overall performance of the model is assessed against experimental data. On this basis, the effects of different functionals, pairing correlations, deformation, and other relevant factors on nuclear level densities are examined. The results show that the present framework provides a good description of the experimental level density and reproduces the s-wave neutron resonance spacings with an accuracy comparable to that of the best existing global models. Furthermore, differences among the adopted relativistic density functionals in the nucleon effective mass at saturated nuclear matter are transmitted to the predicted level densities and constitute the main source of the differences among the results obtained with the three functionals.