QCD Phase Diagram and the Critical Point

The crucial properties of QCD vacuum -- confinement and chiral symmetry breaking -- undergo qualitative changes  at sufficiently high temperatures and/or baryon densities. Determining where on the phase diagram and how the transitions between QCD phases are accomplished is the major goal of heavy-ion collision experiments as well as of theoretical efforts, including first-principle lattice calculations. Is there a critical point in QCD separating crossover from the first order transition on the boundary between quark-gluon plasma and hadron gas phases? Heavy-ion collision experiments could answer this question by focusing on universal signatures characteristic of critical phenomena.