Determination of the QCD Strong Coupling

Abstract

The idea that hadronic decays of the $\tau$-lepton could provide an ideal laboratory for studying hadronic weak currents at low and intermediate energy was first proposed in (Schilcher K, Tran MD (1984) Phys Rev D 29:570, [1]). In fact, in the light-quark sector the QCD strong coupling can now be determined with high accuracy from experimental data on $\tau$-lepton decay (Davier M, Höcker A, Zhang Z (2006) Rev Mod Phys 78:1043, [2]), (Pich A, Rodriguez-Sanchez A (2016) Phys Rev D 94:034027, [3]). After extrapolation of this value to the Z-boson mass there is excellent agreement with independent determinations in that region.