Studies of the equation-of-state of nuclear matter by heavy-ion collisions at intermediate energy in the multi-messenger era

TL;DR

This paper reviews experimental progress in understanding the nuclear matter equation-of-state at high densities through heavy-ion collisions, emphasizing recent multi-messenger astronomy insights into symmetry energy and neutron star properties.

Contribution

It provides a comprehensive review of heavy-ion collision results related to the high-density EoS and explores their connection with multi-messenger astronomy findings.

Findings

Progress in deriving the symmetric matter term of the EoS.

Recent results on symmetry energy at high densities.

Connections between heavy-ion collision data and neutron star observations.

Abstract

The study of the equation-of-state (EoS) describing the properties of nuclear matter away from the normal conditions is a relevant and intriguing topic of modern nuclear physics. The last decades have witnessed a substantial experimental progress in derivation of the symmetric matter term of the EoS and of the so-called symmetry energy for the asymmetric matter, especially at densities below the saturation point. But it is only in recent years that the opening of the multi-messenger astronomy era, triggered by detection of gravitational waves due to the neutron star mergers, has renewed and enlarged the interest in high-density EoS, being the main ingredient for determining the structure and properties of neutron stars. In this paper we review our knowledge obtained from heavy-ion collisions up to the 1 GeV/nucleon regime, on the EoS above nuclear saturation density. Special emphasis is given on the still few results on symmetry energy at high densities and their interconnections with multi-messenger astronomy findings.