# Investigating the topological structure of quenched lattice QCD with overlap fermions by using multi-probing approximation

## TL;DR

This paper uses multi-probing approximation with overlap fermions to analyze the topological structure of quenched lattice QCD, finding results consistent with all-scale topological density and extracting pseudoscalar glueball mass.

## Contribution

It introduces a multi-probing approximation method to study topological structures in quenched lattice QCD, providing more accurate insights than eigenmode expansion.

## Key findings

- Results are consistent with all-scale topological density.
- Multi-probing reveals structures closer to all-scale density than eigenmode expansion.
- Pseudoscalar glueball mass is successfully extracted.

## Abstract

The topological charge density and topological susceptibility are determined by multi-probing approximation using overlap fermions in quenched SU(3) gauge theory. Then we investigate the topological structure of the quenched QCD vacuum, and compare it with results from the all-scale topological density, the results are consistent. Random permuted topological charge density is used to check whether these structures represent underlying ordered properties. Pseudoscalar glueball mass is extracted from the two-point correlation function of the topological charge density. We study $3$ ensembles of different lattice spacing $a$ with the same lattice volume $16^{3}\times32$, the results are compatible with the results of all-scale topological charge density, and the topological structures revealed by multi-probing are much closer to all-scale topological charge density than that by eigenmode expansion.