Thermal QCD phase transition and its scaling window from Wilson twisted mass fermions

TL;DR

This study explores the thermal phase transition in QCD using lattice simulations with Wilson twisted mass fermions, identifying scaling behaviors and estimating the critical temperature in the chiral limit.

Contribution

Introduces a novel chiral order parameter and analyzes the scaling properties of the QCD phase transition with Wilson twisted mass fermions across various pion masses.

Findings

Results support $O(4)$ universal scaling at physical pion mass

Scaling violations observed at larger masses

Estimated critical temperature in the chiral limit is provided

Abstract

We investigate the thermal QCD phase transition and its scaling properties on the lattice. The simulations are performed with $N_f=2+1+1$ Wilson twisted mass fermions at pion masses from physical up to heavy quark regime. We introduce a novel chiral order parameter, which is free from linear mass contributions and turns out to be very useful for the study of scaling behaviour. Our results are compatible with $O(4)$ universal scaling for the physical pion mass and the temperature range $[120:300]$ MeV. Violations to scaling at larger masses and other possible scenarios, including mean field behaviour and $Z(2)$ scaling scenario are also discussed. We provide an estimation for the critical temperature in the chiral limit $T_0$.