Neutron stars exclude light dark baryons

TL;DR

The paper demonstrates that the existence of neutron stars with masses above 0.7 solar masses constrains the properties of hypothetical light dark baryons, requiring them to be heavier than 1.2 GeV or have strong self-interactions.

Contribution

It provides new astrophysical constraints on light dark baryons based on neutron star observations, excluding certain mass ranges and interaction types.

Findings

Neutron stars above 0.7 solar masses exclude light dark baryons below 1.2 GeV.

Such particles must have strong self-interactions or be heavier than 1.2 GeV.

Constraints impact models of baryogenesis, dark matter, and mirror worlds.

Abstract

Exotic new particles carrying baryon number and with mass of order the nucleon mass have been proposed for various reasons including baryogenesis, dark matter, mirror worlds, and the neutron lifetime puzzle. We show that the existence of neutron stars with mass greater than 0.7 $M_\odot$ places severe constraints on such particles, requiring them to be heavier than 1.2 GeV or to have strongly repulsive self-interactions.