Isovector properties of the Gogny interaction

TL;DR

This paper analyzes the isovector properties of the Gogny nuclear interaction in homogeneous matter, highlighting discrepancies with empirical data and suggesting improvements in the fitting procedures for these functionals.

Contribution

It provides analytical expressions for properties of nuclear matter and evaluates 11 Gogny parametrizations, revealing their limitations in isovector sector modeling.

Findings

Most Gogny interactions have low symmetry energy slope values.

Gogny interactions show limited isospin dependence in mass-radius predictions.

Current Gogny functionals need better fitting of isovector properties.

Abstract

We analyse the properties of the Gogny interaction in homogeneous matter, with special emphasis on the isovector sector. We provide analytical expressions for both the single-particle and the bulk properties of symmetric and asymmetric nuclear matter. We perform an extensive analysis of these properties using 11 parametrizations extracted from the literature. We find that most Gogny interactions have low values for the slope of the symmetry energy, outside the range of empirically extracted values. As a test of extreme isospin dependence, we also study the mass-radius relations implied by the different Gogny equations of state. Our results call for a more careful fitting procedure of the isovector properties of Gogny functionals.