Probing the QCD vacuum with overlap fermions

TL;DR

This paper investigates the structure of the QCD vacuum using low-lying eigenvectors of the overlap-Dirac operator, providing evidence for the role of instantons through local chirality analysis.

Contribution

It introduces a method to probe the QCD vacuum with overlap fermions and demonstrates the presence of local chirality consistent with instanton dominance.

Findings

Eigenmodes show local chirality consistent with instanton models

Supports the significance of instantons in the QCD vacuum

Uses a novel local chirality parameter for analysis

Abstract

We use low lying eigenvectors of the overlap-Dirac operator as a probe of the QCD vacuum. If instantons play a significant role one would expect the low lying eigenmodes of the overlap-Dirac operator to consist mainly of the mixed ``would be zero modes''. Then, the eigenmodes should exhibit local chirality. Studying a recently introduced local chirality parameter, we find evidence supporting this picture.