000002065 001__ 2065
000002065 005__ 20200804051326.0
000002065 037__ $$aBELLE2-CONF-PH-2020-010
000002065 041__ $$aeng
000002065 100__ $$aThe Belle II Collaboration 
000002065 245__ $$a$\tau$ lepton mass measurement at Belle II
000002065 260__ $$a$$c2020-08-04
000002065 300__ $$a18
000002065 520__ $$aThe reconstruction of tau-pair production, $\epem \to \tau^{+}\tau^{-}$, from the subsequent 3-prong  ($\tau^{+} \rightarrow \pi^{+} \pi^{-} \pi^{+} \bar{\nu}_{\tau}$) and 1-prong ($\tau^{-} \to \ell^{-} \bar{\nu}_{\ell} \nu_{\tau}$, $\tau^{-} \to h^{-} \nu_{\tau}$ or $\tau^{-} \to \pi^{-} \pi^0 \nu_{\tau}$) decays, is presented using 8.76~\invfb of $\epem $ collision data of {\belletwo} at  the center-of-mass energy $\sqrt{s} = m_{\Upsilon(4S)}$. The pseudomass technique developed by the ARGUS experiment is used to measure the $\tau$-lepton mass $m_{\tau}$ in the 3-prong $\tau^{+} \to \pi^{+} \pi^{-} \pi^{+} \bar{\nu}_{\tau} $ decay, resulting in $m_{\tau} = 1777.28  \pm 0.75~{\rm (stat)} \pm 0.33 ~{\rm (syst)}\mevcc$. 
000002065 6531_ $$atau lepton
000002065 6531_ $$atau mass
000002065 8560_ $$feduard.de.la.cruz.burelo@desy.de
000002065 8564_ $$uhttps://docs.belle2.org/record/2065/files/BELLE2-CONF-PH-2020-010.pdf