14th International Workshop on e⁺e⁻ collisions from Phi to Psi 2026

Session

Tau Physics

8 Jun 2026, 18:05

Scuola Normale Superiore, Aula Dini, Palazzo del Castelletto (Pisa)

Conveners

Tau Physics

• Fedor Ignatov (University of Liverpool)

19. $\tau$ lepton physics at Belle and Belle II

Yipu Liao

08/06/2026, 18:05

The Belle and Belle II experiments have collected a $1.6~\mathrm{ab}^{-1}$ sample of $e^+e^-$ collision data at center-of-mass energies near the $\Upsilon(nS)$ resonances. This sample contains approximately 1.3 billion $e^+e^-\to \tau^+\tau^{-}$ events. We use the Belle and Run 1 Belle II data samples to search for lepton-flavor violating decays, presenting searches for the decays $\tau \to...

38. The strong coupling from hadronic $\tau$ decays including $\tau\to \pi^- \pi^0 \nu_\tau$ from Belle

Lucas Mansur (Johannes Gutenberg-Universität Mainz)

08/06/2026, 18:25

Inclusive hadronic $\tau$ decays provide one of the most precise extractions of the QCD coupling, $\alpha_s$, from experimental data. For a long time, these analyses relied on ALEPH and OPAL inclusive spectral functions, which were based on measurements of the dominant decay modes but necessitated Monte Carlo simulations for subleading decay channels. We have recently demonstrated that these...