Speaker
Description
We report recent results on $B$ decays from Belle experiment at KEKB collider. $B \to D^{*} \tau \bar{\nu}_{\tau}$ mode is sensitive to probe New Physics such as charged Higgs or leptoquark, and the current world average of the branching ratio shows discrepancy from the Standard Model. Belle has performed a new measurement of this mode using tau decays to hadronic final states, which is essentially independent of previous measurements from Belle. With this method, we have measured the tau lepton polarization in $B \to D^{*} \tau \bar{\nu}_{\tau}$ for the first time. We also report the full angular analysis of $B \to K^{*} \ell^{+} \ell^{-}$ to extract form factor variables such as $P_{5}'$. The measurement is performed separately for $B \to K^{*} e^{+} e^{-}$ and $B \to K^{*} \mu^{+} \mu^{-}$ modes, which makes it possible to study lepton universality on these variables. The analyses are based on the full data set of Belle containing 772 million $B\bar{B}$ pairs.
