Strong coupling constant from moments of quarkonium correlators revisited

TL;DR

This paper refines the determination of the strong coupling constant in QCD by analyzing moments of quarkonium correlators with improved lattice calculations and continuum extrapolations, resulting in a precise value of alpha_s at the Z boson mass scale.

Contribution

It provides a new, more accurate determination of the strong coupling constant using updated lattice QCD data and careful continuum extrapolation techniques.

Findings

Determined $ m ar{ ext{MS}}$ Lambda parameter as 332 ± 17 ± 2 MeV.

Calculated $ m ext{alpha}_s^{n_f=5}(M_Z)$ as 0.1177(12).

Performed a detailed continuum extrapolation of quarkonium moments.

Abstract

We revisit previous determination of the strong coupling constant from moments of quarkonium correlators in (2+1)-flavor QCD. We use previously calculated moments obtained with Highly Improved Staggered Quark (HISQ) action for five different quark masses and several lattice spacings. We perform a careful continuum extrapolations of the moments and from the comparison of these to the perturbative result we determine the QCD Lambda parameter, $\Lambda_{\overline{MS}}^{n_f=3}=332 \pm 17 \pm 2(scale)$ MeV. This corresponds to $\alpha_s^{n_f=5}(\mu=M_Z)=0.1177(12)$.