Nf=2+1 dynamical Wilson quark simulation toward the physical point

TL;DR

This paper reports preliminary lattice QCD simulations with 2+1 flavors approaching physical quark masses, using improved actions and advanced algorithms to analyze meson and hadron spectra.

Contribution

It introduces a simulation approach with nonperturbatively O(a)-improved Wilson quarks and domain-decomposed HMC algorithm to reach near-physical quark masses.

Findings

Pseudoscalar meson masses from 730 MeV to 210 MeV.

Initial results on hadron spectrum and chiral analysis.

Discussion of algorithmic improvements and issues.

Abstract

We present preliminary results of the PACS-CS project which simulates 2+1 flavor lattice QCD toward the physical point with the nonperturbatively O(a)-improved Wilson quark action and the Iwasaki gauge action. Calculations are carried out at beta=1.9 on a 32^3x64 lattice with the use of the domain-decomposed HMC algorithm to reduce the up-down quark mass. The resulting pseudoscalar meson masses range from 730 MeV down to 210 MeV. We discuss the physical results including the chiral analysis in the pseudoscalar meson sector and the hadron spectrum. Some algorithmic issues are also discussed.