Phase diagram of the three-dimensional NJL model

With the exception of confinement the three-dimensional Nambu-Jona-Lasinio (NJL3) model incorporates many of the essential properties of QCD. We discuss the critical properties of the model at non-zero temperature T and/or non-zero chemical potential μ. We show that the universality class of the thermal transition is that of the d = 2 classical spin model with the same symmetry. We provide evidence for the existence of a tricritical point in the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$(\mu,T)$\end{document}-plane. We also discuss numerical results by Handset al. which showed that the system is critical for \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\mu > \mu_c$\end{document} and the diquark condensate is zero.