The Phases of QCD in Heavy Ion Collisions and Compact Stars

TL;DR

This paper reviews the search for a critical point in the QCD phase diagram through heavy ion collisions and discusses phenomena in cold dense quark matter relevant to compact stars.

Contribution

It synthesizes current understanding of QCD phase transitions, experimental signatures, and implications for compact star physics, highlighting recent developments.

Findings

Signatures of the QCD critical point in heavy ion collisions

Expected phenomena in cold dense quark matter like color superconductivity

Implications for the physics of compact stars

Abstract

I review arguments for the existence of a critical point in the QCD phase diagram as a function of temperature and baryon chemical potential. I describe how heavy ion collision experiments at the SPS and RHIC can discover the tell-tale signatures of such a critical point, thus mapping this region of the QCD phase diagram. I then review the phenomena expected in cold dense quark matter: color superconductivity and color-flavor locking. I close with a snapshot of ongoing explorations of the implications of recent developments in our understanding of cold dense quark matter for the physics of compact stars.