Orateur
Shigeki Hirose
(Nagoya University)
Description
The ratio of branching fractions $R(D^{(*)}) \equiv \mathit{BF}(\bar{B} \rightarrow D^{(*)} \tau^- \bar{\nu}_\tau) / \mathit{BF}(\bar{B} \rightarrow D^{(*)} \ell^- \bar{\nu}_\tau)$ (where $\ell^- = e^-, \mu^-$) from Belle, BaBar and LHCb showed about 4$\sigma$ deviation from the SM predictions as of 2015. In this talk, Belle's two measurements for the $\bar{B} \rightarrow D^{(*)} \tau^- \bar{\nu}_\tau$ decay in 2016 will be introduced. These measurements include the first application of the semileptonic tagging to the $R(D^*)$ measurement and the first measurement of the $\tau$ polarization using the hadronic tagging and the hadronic tau decays. Along with the results of the $\bar{B} \rightarrow \tau^- \bar{\nu}_\tau$ measurements, compatibility with the SM and the type-II Two-Higgs-Doublet Model will be discussed.
Author
Shigeki Hirose
(Nagoya University)
