Lattice calculation of low energy constants with Ginsparg-Wilson type fermions

TL;DR

This paper reports a lattice QCD calculation of low energy constants using Ginsparg-Wilson fermions, providing precise values for decay constants, quark masses, and chiral condensate with systematic comparison of methods.

Contribution

It introduces a systematic lattice calculation of low energy constants with Ginsparg-Wilson fermions and compares multiple computational approaches for accuracy.

Findings

Consistent determination of f_pi and f_K decay constants.

Accurate estimates of light and strange quark masses.

Quantitative values for the chiral condensate.

Abstract

We present a quenched lattice calculation of low energy constants using the chirally improved Dirac operator. Several lattice sizes at different lattice spacings are studied. We systematically compare various methods for computing these quantities, using pseudoscalar and axial vector correlators. We find consistent results for the different approaches, giving rise to f_\pi = 96(2)(4) MeV, f_K = 106(1)(8) MeV, f_K/f_\pi=1.11(1)(2), Sigma= -(286(4)(31) MeV)^3, the average light quark mass m = 4.1(2.4) MeV and m_s = 101(8) MeV.