Mirror Neutron Stars: How QCD can be used to study dark matter through gravitational waves

Abstract

Given the lack of empirical evidence of weakly interacting dark matter, it is reasonable to look to other candidates such as a confining dark sector with a similar number of particles as the standard model. Twin Higgs mirror matter is one such model that is a twin of the standard model with particles masses 3--6 times heavier than the standard model that solves the hierarchy problem. This generically predicts mirror neutron stars, degenerate objects made entirely of mirror nuclear matter. We find their structure using a realistic equation of state from crust (nuclei) to core (relativistic mean-field model) and scale the particle masses using lattice QCD results. We find that mirror neutron stars have unique signatures that are detectable via gravitational waves and binary pulsars, that provides an intriguing possibility for probing dark matter.

Comments: prepared for the proceedings of Quark Matter 2022. 6 pages, 1 figure