Chiral extrapolations with small sea quark mass data in two-flavor lattice QCD

TL;DR

This study investigates the light hadron spectrum and quark masses in two-flavor lattice QCD with very small sea quark masses, comparing different chiral extrapolation methods including Wilson chiral perturbation theory.

Contribution

It introduces the application of Wilson chiral perturbation theory with $O(a^2)$ terms to analyze lattice QCD data at small sea quark masses.

Findings

WChPT effectively describes data with small sea quark masses.

Inclusion of $O(a^2)$ terms influences quark mass estimates.

Chiral extrapolations using WChPT are viable and informative.

Abstract

We present results on the light hadron spectrum and quark mass in two-flavor QCD calculated with small sea quark masses down to $m_{PS}/m_{V}=0.35$. The configurations are generated using the RG improved gauge and tadpole-improved clover quark action at $\beta=1.8$, where $a^{-1} \simeq 1$ GeV. Chiral extrapolations are made using not only polynomials and ChPT in the continuum but also formulae of Wilson chiral perturbation theory (WChPT) including $O(a^2)$ chiral breaking terms. We examine the viability of WChPT and its influence on quark masses.