Related papers: Rare tau decays at Belle

We present a study of a singly Cabibbo-suppressed decay $\Lambda_c^+\to{}pK_S^0K_S^0$ and a Cabibbo-favored decay $\Lambda_c^+\to{}pK_S^0\eta$ based on 980 $\rm fb^{-1}$ of data collected by the Belle detector, operating at the KEKB…

Recent results of baryonic B decays from Belle are reported. This study is done by a 78 fb$^{-1}$ data sample, consisting of $85.0 \pm 0.5$ million $B\bar{B}$ pairs, collected by the Belle detector at the KEKB asymmetric energy $e^+e^-$…

We report a measurement of the branching fraction of $B \to K^{\ast}(892)\ell^+\ell^-$ decays, where $\ell^+\ell^- = \mu^+\mu^-$ or $e^+e^-$, using electron-positron collisions recorded at an energy at or near the $\Upsilon(4S)$ mass and…

Belle II experiment at the SuperKEKB collider is a major upgrade of the Belle experiment at the KEKB asymmetric e^+e^- collider at the KEK. The experiment will focus on the search for new physics beyond the standard model via high precision…

We present here the major results obtained in $\tau$ physics by the Belle and Belle II experiments. For the Belle II experiment, we also discuss prospects for improved measurements of the $\tau$ lepton properties, new results in Michel…

We present a measurement of angular observables and a test of lepton flavor universality in the $B\to K^\ast \ell^+\ell^-$ decay, where $\ell$ is either $e$ or $\mu$. The analysis is performed on a data sample corresponding to an integrated…

We report recent results for lepton flavor violating (LFV) tau decays obtained at Belle and BaBar with the world-largest data samples.

The LHCb Collaboration's measurement of R_K = B(B+ -> K+ mu+ mu-)/B(B+ -> K+ e+e-) lies 2.6 sigma below the Standard Model prediction. Several groups suggest this deficit to result from new lepton non-universal interactions of muons. But…

Belle II is an experiment designed to study billions of $\tau$-lepton, $b$- and $c$-quark decays observed with low background in asymmetric-energy electron-positron collisions at the SuperKEKB $B$-factory. In March 2019, the newly completed…

We present a measurement of the ratio $R_\mu = \mathcal{B}(\tau^-\to \mu^-\bar\nu_\mu\nu_\tau) / \mathcal{B}(\tau^-\to e^-\bar\nu_e\nu_\tau)$ of branching fractions $\mathcal{B}$ of the $\tau$ lepton decaying to muons or electrons using…

We search for the charmless B^0 decay with final state particles p Lambdabar pi^- gamma using the full data sample that contains 772 * 10^6 B Bar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB…

We present the results of a search for the radiative decay (B -> K eta' gamma) and find evidence for (B^+ -> K^+ eta' gamma) decays at the 3.3 standard deviation level with a partial branching fraction of (3.6 +/- 1.2 +/- 0.4) x 10e-6,…

We report the first measurement of the $\tau$ lepton polarization in the decay ${\bar B} \rightarrow D^* \tau^- {\bar\nu_{\tau}}$ as well as a new measurement of the ratio of the branching fractions $R(D^{*}) = \mathcal{B}({\bar B}…

We present three analyses based on data samples collected by the Belle detector at the KEKB e+e- asymmetric energy collider. The first one contains the measurement of the branching fractions and q^2 distributions of exclusive charmless…

Recent BABAR and Belle results on rare B decays involving photons or lepton pairs are reviewed. New preliminary limits from both experiments for B-->rho gamma and B-->omega gamma, and from BABAR for B --> K nu nu and B --> tau nu are…

Using 121.4 fb^{-1} of data collected with the Belle detector at the Y(5S) resonance at the KEKB asymmetric-energy e^+e^- collider, we report evidence for the B_s^0 -> Lambda_c^+ Lambda-bar pi^- decay mode with a measured branching fraction…

Many models for physics beyond the Standard Model predict lepton-flavour violating decays of charged leptons at a level which may become observable very soon. In the present paper we investigate the decays of a Tau into three charged…

This contribution illustrates a new search for the flavor-changing neutral-current decay ${B^+ \to K^+ \nu \bar \nu}$ performed by the Belle II experiment at the SuperKEKB asymmetric-energy electron-positron collider. In this study, a…

In the two Higgs doublet model type III and in several other extensions of the Standard Model, there are no discrete symmetries that suppress flavor changing couplings at tree level. The experimental observation of the nu_mu -- nu_tau…

We report the first observation of the doubly Cabibbo-suppressed decay, $D^{+}_{s} \to K^{+}K^{+}\pi^{-}$ and the significantly improved measurement of the doubly Cabibbo-suppressed decay, $D^{+} \to K^{+}\pi^{+}\pi^{-}$ using $\textrm{605…