The tau-lepton lifetime represents a fundamental parameter within the Standard Model framework, contributing to the test of lepton flavor universality. Exploiting the vertex detector resolution and the tiny beam spot size at the interaction point, Belle II is expected to improve the present tau-lifetime value. The event topology where one tau decays to three charged pions (3-prong) and the...
Using the Belle II data from the early Phase III data taking, we reconstructed the tau
leptons using the 3-prong τ decays. This decay mode is used for the tau-lepton mass
measurement using the pseudomass technique developed by the ARGUS experiment. Though
this measurement is expected to be limited by statistics and imperfect knowledge of
the detector performance, we foresee that Belle II...
