New Physics search in rare $\tau$ decays at Belle and prospects at Belle II
2017 January 12
We present our recent achievements and ongoing activities about the search for the New Physics using rare decay of $\tau$. The rare decays are categorized into two groups. First one encompasses practically forbidden decays, in particular, the Lepton flavor violating decays are reviewed. The other group includes tau decays with suppressed branching fractions, predicted by the Standard Model. Both of them provide good opportunities to find hints of the New Physics.