Strangeness-driven phase transition in (proto)- neutron star matter

TL;DR

This paper investigates the phase diagram of neutron star matter including hyperons and electrons, revealing strangeness-driven phase transitions that could impact neutrino behavior in supernovae.

Contribution

It introduces a comprehensive analysis of phase transitions in hyperonic matter considering electromagnetic effects and predicts critical points affecting stellar phenomena.

Findings

Electromagnetic interactions significantly influence the phase diagram at sub-saturation densities.

Strangeness-driven phase transitions occur at high densities in stellar matter.

Potential implications for neutrino propagation in supernovae due to critical points.

Abstract

The phase diagram of a system constituted of neutrons, protons, $\Lambda$-hyperons and electrons is evaluated in the mean-field approximation in the complete three-dimensional space given by the baryon, lepton and strange charge. It is shown that the phase diagram at sub-saturation densities is strongly affected by the electromagnetic interaction, while it is almost independent of the electric charge at supra-saturation density. As a consequence, stellar matter under the condition of strangeness equilibrium is expected to experience a first as well as a second-order strangeness-driven phase transition at high density, while the liquid-gas phase transition is expected to be quenched. An RPA calculation indicates that the presence of this critical point might have sizable implications for the neutrino propagation in core-collapse supernovae.