A critical look at V_us determinations from hadronic tau decay data

Abstract

A critical review of hadronic tau decay data based determinations of |V_{us}| is given, focussing on the impact of the slow convergence of the integrated D=2 OPE series for the conventional flavor-breaking sum rule determination and the potential role of as-yet-unmeasured multiparticle contributions to the strange spectral distribution. Additional information obtainable from analyses of inclusive strange decay data alone, and from mixed electroproduction-tau sum rules with much reduced OPE uncertainties, is also discussed. Self-consistency tests are shown to favor determinations which reduce somewhat discrepancies with 3-family unitarity expectations.

7 pages, 4 figures. Prepared for: Proceedings of the 11th International Workshop on Tau Lepton Physics, Manchester, UK, September 13-17, 2010. Results updated for HFAG corrections to October 2010 HFAG tau strange branching fractions. Appendix added, containing numerical OPE results allowing exploration of conventional inclusive flavor-breaking kinematic sum rule determination (eprint only)

References in corpus (11)

• Hadronic Z- and tau-Decays in Order alpha_s^4
• High-Precision c and b Masses, and QCD Coupling from Current-Current Correlators in Lattice and Continuum QCD
• An evaluation of |Vus| and precise tests of the Standard Model from world data on leptonic and semileptonic kaon decays
• alpha_s and the tau hadronic width: fixed-order, contour-improved and higher-order perturbation theory
• Alpha_s(M_Z) from hadronic tau decays
• Update: Accurate Determinations of alpha_s from Realistic Lattice QCD
• The Realistic Lattice Determination of alpha_s(M_Z) Revisited
• Tau Physics: Theory Overview
• V_us From Hadronin Tau Decays
• Status of the Hadronic Tau Determination of V_us
• A Mixed Tau-Electroproduction Sum Rule for V_us

Cited by in corpus (9)

• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of summer 2016
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2018
• Averages of $b$-hadron, $c$-hadron, and $\tau$-lepton properties as of 2021
• Predicting the tau strange branching ratios and implications for V_{us}
• A resolution of the inclusive flavor-breaking $\tau$ $|V_{us}|$ puzzle
• NNLO low-energy constants from flavor-breaking chiral sum rules based on hadronic tau-decay data
• Evidence against naive truncations of the OPE from $e^{+}{e}^{-}\to$ hadrons below charm
• Status and progress of the HFLAV-Tau group activities
• Lattice Input on the Inclusive $\tau$ Decay $V_{us}$ Puzzle