Strong coupling constant from moments of quarkonium correlators revisited

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 ${\alpha }_s^{n_f=5}(\mu =M_Z)=0.1177(12)$.

Comments: 24 pages, 6 figures; data of Figs. 2-4 among the source files; primary data (figs. 1 and 6) available through arXiv:1901.06424)