New solution to the hyperon puzzle of neutron stars: Quantum many-body effects

TL;DR

This paper introduces a quantum many-body approach using Dyson-Schwinger equations to resolve the hyperon puzzle in neutron stars, successfully supporting high observed masses and suppressing rapid cooling processes.

Contribution

It presents a novel quantum many-body framework that incorporates strong baryon-meson interactions to produce a stiffer equation of state for neutron star matter.

Findings

Supports neutron star masses up to approximately 2.59 solar masses

Predicts low hyperon and proton fractions in neutron star cores

Suppresses direct Urca processes, preventing fast cooling

Abstract

The hyperon puzzle refers to the challenge of reconciling the existence of hyperons in neutron star cores and the observed high masses of neutron stars. The recent discovery of PSR J0952-0607 ($2.35\pm0.17 M_{\odot}$) has intensified this challenge. Existing solutions fail to achieve such a high mass, and often predict unrealistically fast cooling that is at odds with observations. Here, we propose a novel solution to the hyperon puzzle. Using the Dyson-Schwinger equation approach, we incorporate the quantum many-body effects caused by strong baryon-meson interactions into the equation of state for cold baryonic matter and find it stiff enough to support a maximum hyperon-star mass of $M_{\mathrm{max}} \approx 2.59 M_{\odot}$, which can explain all the observed high neutron-star masses. The resulting proton and hyperon fractions are remarkably low, thus the nucleonic and hyperonic direct Urca processes are significantly suppressed. As a result, fast cooling typically does not occur in ordinary neutron stars.