Dilute Liquid of Instanton and Its Topological Charge Dominate the QCD Vacuum

TL;DR

This paper investigates the structure of the QCD vacuum, demonstrating that a dilute liquid of instantons dominates topological charge fluctuations through combined filtering techniques and lattice QCD analysis.

Contribution

It introduces a combined method using APE smearing, overlap-Dirac operator, and improved cooling to analyze the QCD vacuum structure, highlighting the dominance of instantons.

Findings

Dilute liquid of instantons observed in QCD vacuum

Topological charge fluctuations dominated by instantons

Combined filtering methods effectively reveal vacuum structure

Abstract

APE smearing and overlap-Dirac operator are combined to filter QCD vacuum configurations. The results obtained from overlap fermions and improved 5Li cooling are compared, both of them exhibit structures of dilute liquid of instanton. Finally the overlap fermions, improved 5Li cooling and APE smearing are combined to calculate the topological charge and identify the structure of QCD vacuum. The results suggest dilute liquid of instanton dominance of topological charge fluctuations in quenched lattice QCD.