Many-body forces, isospin asymmetry and dense hyperonic matter

TL;DR

This paper investigates how the symmetry energy and its slope influence the properties of dense hyperonic matter in neutron stars, using a many-body forces formalism to improve understanding of the equation of state.

Contribution

It introduces a detailed analysis of asymmetric hyperonic matter considering many-body forces, enhancing the modeling of neutron star matter and hyperon star properties.

Findings

The formalism accounts for many-body forces in meson-baryon interactions.

Calculated EoS for asymmetric hyperonic matter relevant for neutron star modeling.

Insights into the impact of symmetry energy parameters on hyperonic matter behavior.

Abstract

The equation of state (EoS) of asymmetric nuclear matter at high densities is a key topic for the description of matter inside neutron stars. The determination of the properties of asymmetric nuclear matter, such as the symmetry energy ($a_{sym}$) and the slope of the symmetry energy ($L_0$) at saturation density, has been exaustively studied in order to better constrain the nuclear matter EoS. However, differently from symmetric matter properties that are reasonably constrained, the symmetry energy and its slope still large uncertainties in their experimental values. Regarding this subject, some studies point towards small values of the slope of the symmetry energy, while others suggest rather higher values. Such a lack of agreement raised a certain debate in the scientific community. In this paper, we aim to analyse the role of these properties on the behavior of asymmetric hyperonic matter. Using the formalism presented in Ref. (R.O. Gomes et al 2014}, which considers many-body forces contributions in the meson-baryon coupling, we calculate the EoS of asymmetric hyperonic matter and apply it to describe hyperonic matter and hyperon stars.