Lattice study of QCD at finite chiral density: topology and confinement

TL;DR

This study uses lattice QCD simulations to explore how a nonzero chiral chemical potential influences topological fluctuations and confinement, revealing that increased chiral density enhances both phenomena and their correlation.

Contribution

It provides the first lattice evidence linking chiral chemical potential to increased topological fluctuations and confinement in QCD.

Findings

Chiral density $ ho_5$ increases with $ ho_5 o ho_5 \\sim \\Lambda_{QCD}^2 \, \\mu_5$ at small $\\mu_5$.

String tension and topological susceptibility grow with $\\mu_5$, indicating enhanced confinement and topological fluctuations.

Strong correlation observed between topological fluctuations and confinement indicators.

Abstract

In this paper we study the properties of QCD at nonzero chiral density $\rho_5$, which is introduced through chiral chemical potential $\mu_5$. The study is performed within lattice simulation of QCD with dynamical rooted staggered fermions. We first check that $\rho_5$ is generated at nonzero $\mu_5$ and in the chiral limit observe $\rho_5 \sim \Lambda_{QCD}^2 \mu_5$. We also test the possible connection between confinement and topological fluctuations. To this end, we measured the topological susceptibility $\chi_{\mbox{\footnotesize top}}$ and string tension $\sigma$ for various values of $\mu_5$. We observed that both string tension and chiral susceptibility grow with $\mu_5$ and there is a strong correlation between these quantities. We thus conclude that the chiral chemical potential enhances topological fluctuations and that these fluctuations can indeed be closely related to the strength of confinement.