Measurement of the τ lifetime from Belle

Abstract

The lifetime of the τ-lepton is measured using the process $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}$, where both τ-leptons decay to $3\pi \nu$. The preliminary result based on 711 fb⁻¹ of data collected on the $\Upsilon \left(4S\right)$ resonance and in the nearby continuum is ${\tau }_{\tau }=(290.18\pm 0.54(\text{stat.})\pm 0.33(\text{syst.}\left)\right)\times {10}^{-15}\text{s}$.