Confinement-deconfinement phase transition in hot and dense QCD at large N

摘要

We conjecture that the confinement-deconfinement phase transition in QCD at large number of colors N and N-f N at T not equal 0 and mu not equal 0 is triggered by the drastic change in theta behavior. The conjecture is motivated by the holographic model of QCD where confinement-deconfinement phase transition indeed happens precisely at the value of temperature T = T-c where theta dependence experiences a sudden change in behavior [A. Parnachev. A. Zhitnitsky, arXiv: 0806.1736 [hep-ph]]. The conjecture is also supported by quantum field theory arguments when the instanton calculations (which trigger the theta dependence) are under complete theoretical control for T > T-c, suddenly break down immediately below T < T-c with sharp changes in the H dependence. Finally, the conjecture is supported by a number of numerical lattice results. We employ this conjecture to study confinement-deconfinement phase transition of dense QCD at large mu in large N limit by analyzing the theta dependence. We find that the confinement-deconfinement phase transition at N-f N happens at very large quark chemical potential mu(c) similar to root N Lambda(QCD). This result agrees with recent findings by McLerran and Pisarski [L. McLerran. R.D. Pisarski. Nucl.Phys. A 796 (2007) 83]. We also speculate on case when N-f similar to N.