Application of chiral perturbation theory to 2+1 flavor lattice QCD with O(a)-improved Wilson quarks

TL;DR

This paper applies chiral perturbation theory to analyze 2+1 flavor lattice QCD data with improved Wilson quarks, focusing on meson properties and finite size effects, and determines key low energy constants.

Contribution

It introduces a detailed analysis of lattice QCD data using chiral perturbation theory, including the detection of chiral logarithms and finite size effects, with new determinations of low energy constants.

Findings

Evidence of chiral logarithms in meson data

Determination of low energy constants

Assessment of finite size effects

Abstract

We apply chiral perturbation theory to the pseudoscalar meson mass and decay constant data obtained in the PACS-CS Project toward 2+1 flavor lattice QCD simulations with the O(a)-improved Wilson quarks. We examine the existence of chiral logarithms in the quark mass range from m_{ud}=47 MeV down to 6 MeV on a (2.8 fm)^3 box with the lattice spacing a=0.09 fm. Several low energy constants are determined. We also discuss the magnitude of finite size effects based on chiral perturbation theory.