Topological Charge in Two Flavors QCD with Optimal Domain-Wall Fermion

TL;DR

This study measures the topological charge in two-flavor QCD lattice simulations using optimal domain-wall fermions, confirming theoretical predictions and estimating the chiral condensate.

Contribution

It introduces a method to accurately compute topological charge using ODWF and the Adaptive Thick-Restart Lanczos algorithm in lattice QCD simulations.

Findings

Topological susceptibility agrees with chiral perturbation theory predictions.

Provides a new estimate of the chiral condensate.

Demonstrates the effectiveness of the Lanczos algorithm in topological charge calculations.

Abstract

We measure the topological charge of the gauge configurations generated by lattice simulations of 2 flavors QCD on a $ 16^3 \times 32 $ lattice, with Optimal Domain-Wall Fermion (ODWF) at $ N_s = 16 $ and plaquette gauge action at $ \beta = 5.90 $. Using the Adaptive Thick-Restart Lanczos algorithm, we project the low-lying modes of the 4D effective Dirac operator of ODWF, and obtain the topological charge and topological susceptibility. Our result of topological susceptibility agrees with the sea-quark mass dependence predicted by the chiral perturbation theory, and provides a determination of the chiral condensate.