Covariant energy density functionals: nuclear matter constraints and global ground state properties

TL;DR

This study investigates how covariant energy density functionals relate to nuclear matter constraints and ground state properties, finding that strict adherence to nuclear matter constraints does not necessarily improve finite nuclei descriptions.

Contribution

It reveals that enforcing nuclear matter property constraints does not guarantee better ground state predictions and highlights the importance of shell effects in finite nuclei modeling.

Findings

Strict nuclear matter constraints do not improve binding energy predictions.

Functionals fitted to finite nuclei often violate some nuclear matter constraints.

Shell effects significantly influence finite nuclei properties beyond nuclear matter parameters.

Abstract

The correlations between global description of the ground state properties (binding energies, charge radii) and nuclear matter properties of the state-of-the-art covariant energy density functionals have been studied. It was concluded that the strict enforcement of the constraints on the nuclear matter properties (NMP) defined in Ref.\ \cite{RMF-nm} will not necessary lead to the functionals with good description of the binding energies and other ground and excited state properties. In addition, it will not substantially reduce the uncertainties in the predictions of the binding energies in neutron-rich systems. It turns out that the functionals, which come close to satisfying these NMP constraints, have some problems in the description of existing data. On the other hand, these problems are either absent or much smaller in the functionals which are carefully fitted to finite nuclei but which violate some NMP constraints. This is a consequence of the fact that the properties of finite nuclei are defined not only by nuclear matter properties but also by underlying shell effects. The mismatch of phenomenological content, existing in all modern functionals, related to nuclear matter physics and the physics of finite nuclei could also be responsible.