Finite temperature QCD: progress and outstanding problems

TL;DR

This paper reviews recent advances in numerical simulations of finite temperature QCD, covering phase transition properties, critical behavior, thermodynamics, and phenomenological models, highlighting progress and unresolved issues.

Contribution

It provides a comprehensive overview of recent numerical results and discusses new developments in phenomenological models related to deconfinement and chiral symmetry restoration in finite temperature QCD.

Findings

Determined the QCD phase transition temperature.

Analyzed the scaling of the Polyakov loop and quark free energy.

Studied critical behavior near the phase transition.

Abstract

I review recent progress in numerical simulations of finite temperature quantum chromodynamics and discuss the status of some outstanding problems. Included is (1) a discussion of recent results determining the temperature of the ``phase transition'' in full QCD, (2) a scaling analysis of the Polyakov loop variable, leading to the determination of a constituent quark free energy, (3) studies of critical behavior near the phase transition in two-flavor QCD, (4) a discussion of problems and new results in thermodynamic simulations with Wilson fermions, (5) recent results in pure gauge theory with a mixed fundamental/adjoint action, and (6) the nonperturbative determination of the equation of state with dynamical fermions included. Finally I mention briefly new developments in efforts to construct a phenomenology of deconfinement and chiral symmetry restoration, namely (7) the dual superconducting model and (8) the instanton model.