Determination of αs from static QCD potential: OPE with renormalon subtraction and lattice QCD

A bstract We determine the strong coupling constant α s from the static QCD potential by matching a theoretical calculation with a lattice QCD computation. We employ a new theoretical formulation based on the operator product expansion, in which renormalons are subtracted from the leading Wilson coefficient. We remove not only the leading renormalon uncertainty of O O (Λ QCD) but also the first r -dependent uncertainty of O (ₐ₂₃³r²) O Λ Q C D 3 r 2. The theoretical prediction for the potential turns out to be valid at the static color charge distance ₌ₒr 0. 8 Λ M S ¯ r ≲ 0. 8 (r ≲ 0. 4 fm), which is significantly larger than ordinary perturbation theory. With lattice data down to ₌ₒr 0. 09 Λ M S ¯ r ∼ 0. 09 (r ∼ 0. 05 fm), we perform the matching in a wide region of r, which has been difficult in previous determinations of α s from the potential. Our final result is α s (M Z 2) = 0. 1179 − 0. 0014 + 0. 0015 with 1. 3% accuracy. The dominant uncertainty comes from higher order corrections to the perturbative prediction and can be straightforwardly reduced by simulating finer lattices.