The strong coupling from tau decays without prejudice

Abstract

We review our recent determination of the strong coupling \alpha_s from the OPAL data for non-strange hadronic tau decays. We find that \alpha_s(m^2_\tau) =0.325+-0.018 using fixed-order perturbation theory, and \alpha_s(m^2_\tau)=0.347+-0.025 using contour-improved perturbation theory. At present, these values supersede any earlier determinations of the strong coupling from hadronic tau decays, including those from ALEPH data.

Comments: 4 pages, contribution to TAU2012; the style file available on arXiv did not process our paper correctly