A new approach to determine the thermodynamics of deconfined matter to high accuracy

TL;DR

This paper introduces a high-precision method combining phase-quenched lattice simulations and perturbation theory to accurately determine the thermodynamics of deconfined QCD matter at high temperatures and finite density.

Contribution

It develops a novel approach that integrates lattice data with high-order perturbative calculations, achieving unprecedented accuracy in QCD thermodynamics.

Findings

Perturbative correction computed up to O(α_s^{7/2})

Enhanced precision in QCD pressure calculations

Effective suppression of nonperturbative effects in the regime

Abstract

We demonstrate that at finite density and sufficiently high temperatures, phase-quenched (PQ) lattice simulations combined with perturbation theory provide a new precision approach to determining the thermodynamics of QCD across a wide arc of the phase diagram where the strong coupling constant $\alpha_s$ remains small. In this regime, nonperturbative pairing effects in the PQ theory are parametrically suppressed, so that the difference between the PQ and full QCD pressures becomes a small perturbative correction. We compute this correction up to and including $O(\alpha_s^{7/2})$ using electrostatic QCD together with a novel numerical method to compute four-loop sum-integrals. This enables the determination of the perturbative QCD pressure with precision beyond the current state of the art while including nonperturbative pure-gluonic contributions from the lattice.