Polyakov loop model with exact static quark determinant in the 't Hooft-Veneziano limit: SU(N) case

Abstract

We construct an exact solution of the $d$-dimensional $SU(N)$ Polyakov loop model with the exact static quark determinant at finite temperature and non-zero baryon chemical potential in the 't~Hooft--Veneziano limit. In the joint large-$N$, large-$N_f$ limit with fixed ratio $\kappa = N_f/N$, the mean-field approximation becomes exact, and the core of the Polyakov loop model reduces to a deformed unitary matrix model, which we solve analytically. In particular, we compute the free energy and its derivatives, the expectation values of the Polyakov loop, and the baryon density, and we describe the phase diagram of the model in detail. We show how the $SU(N)$ case differs from the corresponding $U(N)$ model and how the three-phase structure known from one-dimensional QCD at finite density extends to non-zero coupling.