Chiral and deconfinement properties of the QCD crossover have a different volume and baryochemical potential dependence

TL;DR

This study investigates how the deconfinement and chiral symmetry restoration transitions in QCD differ in their dependence on volume and baryochemical potential using lattice simulations, revealing distinct behaviors.

Contribution

It provides new insights into the different volume and chemical potential dependencies of deconfinement and chiral transitions in QCD from lattice data.

Findings

Deconfinement observables have milder volume dependence.

Chiral transition width remains approximately constant with increasing chemical potential.

Deconfinement transition broadens with increasing baryochemical potential.

Abstract

The crossover from hadronic to quark matter is understood to be both a deconfinement as well as a chiral symmetry restoring transition. Here, we study observables related to both aspects using lattice simulations: the Polyakov loop and its derivatives and the chiral condensate and its derivatives. At zero baryochemical potential, and infinite volume, the chiral and deconfinement crossover temperatures almost agree. However, chiral and deconfinement related observables have a qualitatively different chemical potential and volume dependence. In general, deconfinement related observables have a milder volume dependence. Furthermore, while the deconfinement transition appears to get broader with increasing $\mu_B$, the width as well as the strength of the chiral transition is approximately constant. Our results are based on simulations at zero and imaginary chemical potentials using 4stout-improved staggered fermions with $N_\tau=12$ time-slices and physical quark masses.