Lattice Input on the Inclusive $τ$ Decay $V_{us}$ Puzzle

P. A. Boyle, L. Del Debbio, N. Garron, R. J. Hudspith, E. Kerrane, K. Maltman, J. M. Zanotti

Research output: Contribution to journalArticlepeer-review


Recent analyses of flavor-breaking hadronic-$\tau$-decay-based sum rules produce values of $\vert V_{us}\vert$ $\sim 3\sigma$ low compared to 3-family unitarity expectations. An unresolved systematic issue is the significant variation in $\vert V_{us}\vert$ produced by different prescriptions for treating the slowly converging $D=2$ OPE series. We investigate the reliability of these prescriptions using lattice data for various flavor-breaking correlators and show the fixed-scale prescription is clearly preferred. Preliminary updates of the conventional $\tau$-based, and related mixed $\tau$-electroproduction-data-based, sum rule analyses incorporating B-factory results for low-multiplicity strange $\tau$ decay mode distributions are then performed. Use of the preferred FOPT $D=2$ OPE prescription is shown to significantly reduce the discrepancy between 3-family unitarity expectations and the sum rule results.
Original languageEnglish
JournalInternational Journal of Modern Physics: Conference Series
Publication statusPublished - 18 Dec 2014
EventInternational Workshop on e+e- Collisions from Phi to Psi 2013 - Rome, Italy
Duration: 9 Sep 201312 Sep 2013


  • hep-ph
  • hep-ex
  • hep-lat


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