Measurement of the mass of the $\tau$-lepton and an upper limit on the mass difference between ${\tau }^{+}$ and ${\tau }^{-}$

The Belle Collaboration, K. Belous, M. Shapkin +1

The mass of the $\tau$ lepton has been measured in the decay mode $\tau \to 3\pi {\nu }_{\tau }$ using a pseudomass technique. The result obtained from $414{\mathrm{fb}}^{-1}$ of data collected with the…