Signal for the Quark-Hadron Phase Transition in Rotating Hybrid Stars

TL;DR

This paper explores the possibility that rotating hybrid stars can contain quark matter cores with a mixed phase, challenging previous assumptions and proposing observable signals for the quark-hadron phase transition.

Contribution

It demonstrates that neutron stars can host a mixed quark-hadron phase due to their multi-component nature, providing a new perspective on the quark-hadron transition in astrophysics.

Findings

Hybrid stars can contain quark matter cores with a mixed phase.

Observable signatures of quark matter in neutron stars are discussed.

The structure of rotating hybrid stars is characterized.

Abstract

For the past 20 years it had been thought that the coexistence phase of the confined hadronic and quark matter phases, assumed to be a first order transition, was strictly excluded from neutron stars. This, however, was due to a seemingly innocuous idealization which has approximated away important physics. The reason is that neutron stars constitute multi-component bodies rather than single-component ones formerly (and incorrectly) used to describe the deconfinement phase transition in neutron stars. So, contrary to earlier claims, `neutron' stars may very well contain quark matter in their cores surrounded by a mixed-phase region of quark and hadronic matter. Such objects are called hybrid stars. The structure of such stars as well as an observable signature that could signal the existence of quark matter in their cores are discussed in this paper.