The Phases of QCD in Heavy Ion Collisions and 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.

Comments: 29 pages. 4 figures. latex with aipproc. References added and corrected. One version of this review is to appear in the Comments of Nuclear and Particle Physics section of Comments on Modern Physics. Other versions were contributed to the proceedings of the Conference on Intersections of Nuclear and Particle Physics, Quebec, May 2000 and to the proceedings of the 40th Zakopane School of Theoretical Physics, June 2000