2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/177730Recent experimental results on hadronic tau decays into strange particles by the OPAL collaboration are employed to determine V_us and m_s from moments of the invariant mass distribution. Our results are V_us = 0.2208+-0.0034 and m_s(2 GeV) = 81+-22 MeV. The error on V_us is dominated by experiment, and should be improvable in the future. Nevertheless, already now our result is competitive to the standard extraction of V_us from K_e3 decays, and it is compatible with unitarity.4 pages, 1 figureHigh Energy Physics - PhenomenologyHigh Energy Physics - ExperimentHigh Energy Physics - Latticetext