Finite Temperature Lattice QCD in the Large N Limit

TL;DR

This paper reviews recent analytic approaches to the deconfinement transition in large N lattice QCD, compares these with Monte Carlo simulations, and introduces new results on the deconfinement temperature and effective models.

Contribution

It provides a self-contained review of analytic models for deconfinement in large N lattice QCD, including new comparisons with Monte Carlo data and insights into effective Polyakov loop models.

Findings

Analytic models predict deconfinement temperature with good accuracy in 2+1 dimensions.

Weak coupling models relate to exactly solvable matrix models.

Results show good agreement with simulations away from the continuum limit.

Abstract

Our aim is to give a self-contained review of recent advances in the analytic description of the deconfinement transition and determination of the deconfinement temperature in lattice QCD at large N. We also include some new results, as for instance in the comparison of the analytic results with Montecarlo simulations. We first review the general set-up of finite temperature lattice gauge theories, using asymmetric lattices, and develop a consistent perturbative expansion in the coupling $\beta_s$ of the space-like plaquettes. We study in detail the effective models for the Polyakov loop obtained, in the zeroth order approximation in $\beta_s$, both from the Wilson action (symmetric lattice) and from the heat kernel action (completely asymmetric lattice). The distinctive feature of the heat kernel model is its relation with two-dimensional QCD on a cylinder; the Wilson model, on the other hand, can be exactly reduced to a twisted one-plaquette model via a procedure of the Eguchi-Kawai type. In the weak coupling regime both models can be related to exactly solvable Kazakov-Migdal matrix models. The instability of the weak coupling solution is due in both cases to a condensation of instantons; in the heat kernel case, it is directly related to the Douglas-Kazakov transition of QCD2. A detailed analysis of these results provides rather accurate predictions of the deconfinement temperature. In spite of the zeroth order approximation they are in good agreement with the Montecarlo simulations in 2+1 dimensions, while in 3+1 dimensions they only agree with the Montecarlo results away from the continuum limit.