Clear correlation between monopoles and the chiral condensate in SU(3) QCD

TL;DR

This study uses lattice QCD simulations to explore the relationship between monopoles and chiral symmetry breaking in SU(3) QCD, revealing a strong correlation especially in the confinement phase and suggesting magnetic fields around monopoles may catalyze chiral symmetry breaking.

Contribution

It demonstrates a direct correlation between monopoles and the chiral condensate in SU(3) QCD, providing evidence for monopole dominance and local condensate enhancement near monopoles in lattice simulations.

Findings

Monopoles are strongly correlated with the chiral condensate in the confinement phase.

Chiral symmetry is restored in the deconfined phase for both Abelian and monopole sectors.

Large local chiral condensate values are found near monopoles, indicating a possible magnetic catalysis mechanism.

Abstract

We study spontaneous chiral-symmetry breaking in SU(3) QCD in terms of the dual superconductor picture for quark confinement in the maximally Abelian (MA) gauge, using lattice QCD Monte Carlo simulations with four different lattices of $16^4$, $24^4$, $24^3\times 6$ at $\beta=6.0$ (i.e., the spacing $a \simeq$ 0.1 fm), and $32^4$ at $\beta=6.2$ (i.e., $a \simeq$ 0.075 fm), at the quenched level. First, in the confinement phase, we find Abelian dominance and monopole dominance in the MA gauge for the chiral condensate in the chiral limit,using the two different methods of i) the Banks-Casher relation with the Dirac eigenvalue density and ii) finite quark-mass calculations with the quark propagator and its chiral extrapolation. In the high-temperature deconfined phase, the chiral restoration is observed also for the Abelian and the monopole sectors. Second, we investigate local correlation between the chiral condensate and monopoles, which topologically appear in the MA gauge. We find that the chiral condensate locally takes a quite large value near monopoles. As an interesting possibility, the strong magnetic field around monopoles is responsible to chiral symmetry breaking in QCD, similarly to the magnetic catalysis.