High-Precision Charm-Quark Mass and QCD Coupling from Current-Current Correlators in Lattice and Continuum QCD

TL;DR

This paper combines lattice QCD simulations and four-loop continuum perturbation theory to precisely determine the charm-quark mass and QCD coupling, achieving some of the most accurate results to date.

Contribution

It introduces a novel combination of lattice and continuum methods to improve the precision of charm-quark mass and QCD coupling determinations.

Findings

Charm-quark mass at 3 GeV: 0.986(10) GeV

QCD coupling at 3 GeV: 0.251(6)

Results are among the most accurate to date

Abstract

We use lattice QCD simulations, with MILC gluon configurations and HISQ c-quark propagators, to make very precise determinations of moments of charm-quark pseudoscalar, vector and axial-vector correlators. These moments are combined with new four-loop results from continuum perturbation theory to obtain several new determinations of the MSbar mass of the charm quark and of the MSbar coupling. We find m_c(3GeV)=0.986(10)GeV, or, equivalently, m_c(m_c)=1.268(9)GeV, both for n_f=4 flavors; and alpha_msb(3GeV,n_f=4)=0.251(6), or, equivalently, alpha_\msb(M_Z,n_f=5)=0.1174(12). The new mass agrees well with results from continuum analyses of the vector correlator using experimental data for e+e- annihilation (instead of using lattice QCD simulations). These lattice and continuum results are the most accurate determinations to date of this mass. Ours is also one of the most accurate determinations of the QCD coupling by any method.