Chiral vortical catalysis constrained by LQCD simulations

TL;DR

This paper investigates how rotation affects the QCD phase diagram, using lattice QCD data to inform an effective model that reveals chiral symmetry breaking is enhanced by angular velocity, impacting the critical end point location.

Contribution

It introduces a rotating NJL model with an angular velocity-dependent coupling fitted to lattice QCD data, demonstrating chiral vortical catalysis and its effects on the phase diagram.

Findings

Chiral condensate increases with angular velocity due to running coupling.

Enhanced fluctuations in chiral susceptibility near the transition temperature.

Shift of the critical end point to higher temperatures and chemical potentials.

Abstract

Evidences of vortical effects have been recently found by experiments in heavy ion collisions, instigating new insights into the phase diagram of quantum chromodynamics (QCD). Considering the effect of rotations, lattice QCD data shows that the temperatures for deconfinement and chiral symmetry restoration should increase with real angular velocity, and the dominant effects are related to gluonic degrees of freedom. These findings could be essential for quark models in rotating systems that lack gluonic interactions, which predicts the decreasing of the chiral temperature transition with the angular velocity. To address this issue properly, in this work we apply the two-flavor Nambu--Jona-Lasinio model to explore the phase diagram in a rotating rigid cylinder with constant angular velocity in the mean field approximation. To circumvent the absence of gluons, we propose the application of an effective coupling dependent of the angular velocity, fitted to match the pseudocritical temperature of chiral phase transition in the model through lattice QCD data. Our results indicate that the running coupling induces the enhancement of the chiral condensate as a function of angular velocity, strengthening the breaking of chiral symmetry, an effect previously dubbed as chiral vortical catalysis. For the chiral susceptibility we observe stronger fluctuations around the transition temperature when we consider the running coupling. The phase diagram is affected by these findings shifting the critical end point (CEP) to higher temperatures and chemical potentials.