# PoS(CKM2016)052

$D^*$ and $\tau$ polarization measurements by Belle

K. Adamczyk, On behalf of the BELLE Collaboration

Contribution: pdf

Other files: files

Abstract

Semitauonic $\bar{B} \to D^{(*)} \tau \bar{\nu_{\tau}}$ decays provide a wide variety of observables sensitive to new physics contributions, such as differential distributions and polarizations. Of particular interest is $\tau$ polarization, that cannot be accessed in other semileptonic decays. Furthermore $D^{*}$ polarization can be measured fairly accurately, so it can be good discriminant of some new physics scenarios. Correlations between various observables offer a rich laboratory to investigate the structure of interactions in semitauonic $B$ decays. In this report, preliminary results on the first measurement of $\tau$ polarization and prospects for the $D^*$ polarization measurements are presented.