Holography of the quark matter triple point

Abstract

The quark matter phase diagram is believed to contain two distinguished points, lying on the boundary of the Quark–Gluon Plasma phase: a critical point and a triple point. In the holographic [“AdS/QCD”] approach, the region of relatively low chemical potentials around the phase transition near the critical point may be described using generalizations of the Hawking–Page transition. We propose that the other QGP phase line, beginning at the triple point and rising towards the region of extremely high temperatures and chemical potentials, is described instead by a non-perturbative string effect discovered by Seiberg and Witten. Using an assumed position for the critical point, we are able to use this proposal to obtain a holographic lower bound on the temperature of the triple point. Combined with Shuryak's upper bound on this temperature, this leads to a rough estimate of the location of the triple point, at a temperature of around 70 MeV, and a chemical potential of about 1100 MeV.