Precise αs determination from charmonium sum rules

The strong coupling, alpha(s), governs perturbative Quantum Chromodynamics (QCD) and is one of the free parameters of the Standard Model. We introduce a new method that allows a precise extraction of alpha(s)(m(Z)) from dimensionless ratios of roots of moments of the charm-quark vector correlator. The ratios we use in our analysis have a rather weak logarithmic quark-mass dependence, starting at O(alpha(2)(s)), and can be obtained from experimental data with good precision, since they benefit from positive correlations among the individual experimentally determined moments. We perform a careful and conservative error analysis with special emphasis on uncertainties related to the truncation of perturbation theory, treating the renormalization scales such as to ensure order-by-order convergence. Our final result, with expressions at O(alpha(3)(s)), is alpha(s)(m(Z)) = 0.1168 +/- 0.0019. (C) 2020 The Author(s). Published by Elsevier B.V.