First determination of the strange and light quark masses from full lattice QCD

TL;DR

This paper presents the first lattice QCD calculation to determine the strange and light quark masses using full dynamical quarks, experimental meson masses, and perturbative conversion to the ar scheme, providing precise values.

Contribution

It introduces a full lattice QCD approach with three dynamical quarks and experimental data to accurately compute quark masses, including systematic error analysis.

Findings

Strange quark mass: 76(7) MeV at 2 GeV in ar scheme.

Average u/d quark mass: 2.8(3) MeV at 2 GeV in ar scheme.

Quark mass ratio: 27.4(4).

Abstract

We compute the strange quark mass $m_s$ and the average of the $u$ and $d$ quark masses $\hat m$ using full lattice QCD with three dynamical quarks combined with experimental values for the pion and kaon masses. The simulations have degenerate $u$ and $d$ quarks with masses $m_u=m_d\equiv \hat m$ as low as $m_s/8$, and two different values of the lattice spacing. The bare lattice quark masses obtained are converted to the $\msbar$ scheme using perturbation theory at $O(alpha_s)$. Our results are: $m_s^\msbar$(2 GeV) = 76(0)(3)(7)(0) MeV, $\hat m^\msbar$(2 GeV) = 2.8(0)(1)(3)(0) MeV and $m_s/\hat m$ = 27.4(1)(4)(0)(1), where the errors are from statistics, simulation, perturbation theory, and electromagnetic effects, respectively.