Hadronic tau decays and the strong coupling

Abstract

We provide an overview of recent determinations of the strong coupling, αs, from hadronic τ decays. We contrast two analysis methods, the “truncated-OPE approach” and the “DV-model approach,” highlighting the assumptions going into each of these. We argue that a detailed study based on ALEPH data shows the truncated-OPE approach to be quantitatively unreliable, while the DV-model approach passes all tests. New data for hadronic τ decays from Belle and Belle-II could provide more stringent tests of the DV-model approach, and thus potentially lead to a more precise value of αs from hadronic τ decays.