Constraints for the QCD phase diagram from imaginary chemical potential

Abstract

We present unambiguous evidence from lattice simulations of N_f=3 QCD for two tricritical points in the (T,m) phase diagram at fixed imaginary μ/T=iπ/3 mod. 2π/3, one in the light and one in the heavy quark regime. Together with similar results in the literature for N_f=2 this implies the existence of a chiral and of a deconfinement tricritical line at those values of imaginary chemical potentials. These tricritical lines represent the boundaries of the analytically continued chiral and deconfinement critical surfaces, respectively, which delimit the parameter space with first order phase transitions. It is demonstrated that the shape of the deconfinement critical surface is dictated by tricritical scaling and implies the weakening of the deconfinement transition with real chemical potential. A qualitatively similar effect holds for the chiral critical surface.

arXiv comment7 pages, 5 figures. To appear in the Proceedings of the 28th International Symposium on Lattice Field Theory (Lattice 2010), Villasimius, Sardinia, Italy, June 14-19, 2010

References in corpus (7)

• The QCD phase diagram for small densities from imaginary chemical potential
• Finite density QCD via imaginary chemical potential
• The chiral critical line of N_f=2+1 QCD at zero and non-zero baryon density
• The strongly interacting Quark Gluon Plasma, and the critical behaviour of QCD at imaginary chemical potential
• The order of the Roberge-Weiss endpoint (finite size transition) in QCD
• The 3-state Potts model as a heavy quark finite density laboratory
• The QCD phase diagram at zero and small baryon density