Recent results on QCD thermodynamics: lattice QCD versus Hadron Resonance Gas model

TL;DR

This paper investigates QCD transition temperatures using lattice QCD with improved techniques and compares results with the Hadron Resonance Gas model and Chiral Perturbation Theory, providing insights into the QCD cross-over transition.

Contribution

It extends previous lattice QCD studies with finer lattices and physical quark masses, offering more precise results and comparisons with analytic models and other collaborations.

Findings

Lattice results agree with Hadron Resonance Gas model below transition

Transition temperatures are consistent with Chiral Perturbation Theory predictions

Comparison with hotQCD collaboration highlights methodological differences

Abstract

We present our most recent investigations on the QCD cross-over transition temperatures with 2+1 staggered flavours and one-link stout improvement [JHEP 1009:073, 2010]. We extend our previous two studies [Phys. Lett. B643 (2006) 46, JHEP 0906:088 (2009)] by choosing even finer lattices ($N_t$=16) and we work again with physical quark masses. All these results are confronted with the predictions of the Hadron Resonance Gas model and Chiral Perturbation Theory for temperatures below the transition region. Our results can be reproduced by using the physical spectrum in these analytic calculations. A comparison with the results of the hotQCD collaboration is also discussed.