Hybrid Strangeon Stars

TL;DR

This paper investigates hybrid strangeon stars, which are compact stellar objects with a strange quark matter core, analyzing their structure, astrophysical constraints, and the nature of the strangeon-SQM transition.

Contribution

It introduces the concept of hybrid strangeon stars with a strange quark matter core and examines their astrophysical properties and phase transition conditions.

Findings

Hybrid strangeon stars can satisfy pulsar mass and radius constraints.

The strangeon-SQM mixed phase is disfavored under charge-neutrality conditions.

Hybrid strangeon stars are consistent with observed tidal deformabilities.

Abstract

It was conjectured that the basic units of the ground state of bulk strong matter may be strange-clusters called strangeons, and they can form self-bound strangeon stars that are highly compact. Strangeon stars can develop a strange quark matter (SQM) core at high densities, particularly in the color-flavor-locking phase, yielding a branch of hybrid strangeon stars. We explore the stellar structure and astrophysical implications of hybrid strangeon stars. We find that hybrid strangeon stars can meet various astrophysical constraints on pulsar masses, radii, and tidal deformabilities. Finally, we show that the strangeon-SQM mixed phase is not preferred if the charge-neutrality condition is imposed at the strangeon-SQM transition region.