EoS constraints from nuclear masses and radii in a meta-modeling approach

TL;DR

This study develops a meta-modeling approach for the nuclear equation of state (EoS) that accurately predicts nuclear masses, radii, and skins, and analyzes correlations among EoS parameters using nuclear observables.

Contribution

It introduces a minimal, unified EoS meta-model that reproduces various model predictions and assesses parameter correlations without physical constraints.

Findings

Meta-model reproduces masses, radii, and skins comparable to detailed calculations.

No significant correlations found among EoS parameters.

Strong correlation between symmetry energy slope and neutron skin.

Abstract

The question of correlations among empirical equation of state (EoS) parameters constrained by nuclear observables is addressed in a fully empirical meta-modeling approach. A recently proposed meta-modeling for the nuclear EoS in nuclear matter, is augmented with a single finite size term to produce a minimal unified EoS functional able to describe the smooth part of the nuclear ground state properties. This meta-model can reproduce the predictions of a large variety of models, and interpolate continuously between them. The parameter space is sampled and filtered through the constraint of nuclear mass reproduction. We show that this simple analytical meta-modeling has a predictive power on masses, radii, and skins comparable to full HF or ETF calculations with realistic energy functionals. The covariance analysis on the posterior distribution shows that no physical correlation is present between the different EoS parameters. Concerning nuclear observables, a strong correlation between the slope of the symmetry energy and the neutron skin is observed, in agreement with previous studies.