Related papers: Constraints on R-parity violation from recent Bell…

An analysis of the rare B decays $B\to K^{(*)}\nu\bar\nu$ is presented both within the SM and beyond. The SM predictions for the branching ratios are updated and uncertainties reduced. For the NP analysis both a model independent approach…

We study the branching ratios of rare K and B decays in models with minimal flavour violation, using the presently available information from the universal unitarity triangle analysis and from the measurements of Br(B -> X_s gamma), Br(B ->…

We report a search for the lepton-flavor-violating decays $\tau^{\pm}\to\ell^{\pm}\alpha$~($\ell=e,\mu$), where $\alpha$ is an undetected spin-0 particle, such as an axion-like particle using $736\times10^{6}$ tau lepton pairs collected by…

We present measurements of B+ -> Dbar*0 tau+ nu_tau and B+ -> Dbar^0 tau+ nu_tau decays in a data sample of 657 x 10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We find 446^{+58}_{-56} events…

We have studied hadronic tau decay modes involving an eta meson using 490 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. The following branching fractions have been measured: B(tau- -> K- eta…

We study the rare decays $B^{+}_u\to \pi^{+}\ell^{+}\ell^{-}$, $\rho^{+}\ell^{+}\ell^{-}$ and $B^{0}_d \to \ell^{+} \ell^{-}(\ell=e,\mu)$ in the R-parity violating supersymmetric standard model. From the latest upper limits of…

We report a study of $\tau$ lepton decays involving $\Ks$ with a 669 fb$^{-1}$ data sample accumulated with the Belle detector at the KEKB asymmetric-energy $e^{+}e^{-}$ collider. The branching fractions have been measured for the $\tauTO…

We study in the framework of R-parity violating supersymmetric theories the effect of R-parity violation due to the operator L_i L_j \bar{E_k} on the (V-A) structure of the muon decay. The precisely measured muon decay parameters can…

We report on a search for the lepton flavor violating tau- -> mu- gamma and tau- -> e- gamma decays based on 535/fb of data accumulated at the Belle experiment. No signal is found and we set 90% confidence level upper limits on the…

A measurement of the tau- --> K- pi0 nu_tau branching fraction has been made using 230.2 fb-1 of data recorded by the BABAR detector at the PEP-II e+ e- collider, located at the Stanford Linear Accelerator Center (SLAC), at a center of mass…

Recently, the CDF and D{\O} collaborations have claimed that the CP violating phase in $B_s^0-\bar{B}_s^0$ mixing is large, which is contrary to the expectations in the Standard Model. Such a large phase suggests New Physics contributions…

We study the decays $B\to K^{(*)}\ell^+\ell^-$ and $B_s\to \ell^+\ell^- (\ell=e,\mu)$ in the minimal supersymmetric standard model with R-parity violation (RPV). From the recent measurements of their branching ratios, we have derived new…

In this work we consider the implications of current $b \to s \ell^+ \ell^-$ ($\ell=e,\,\mu$) measurements on several $B \to K^* \tau^+ \tau^-$ observables under the assumption that the possible new physics can have both universal as well…

Charged lepton flavor violation is forbidden in the Standard Model but possible in several new physics scenarios. In many of these models, the radiative decays $\tau^{\pm}\rightarrow\ell^{\pm}\gamma$ ($\ell=e,\mu$) are predicted to have a…

We present a new measurement of the purely leptonic decay B- -> tau- nu_tau-bar with a semileptonic B tagging method, using a data sample containing 657*10^6 BB-bar pairs collected with the Belle detector at the KEKB asymmetric e+e-…

The recent Belle and BaBar measurements of the branching ratio of $B^+ \to \tau^+ \nu_\tau$ indicate a significant deviation from the Standard Model prediction. We demonstrate that this measurement has a serious impact on models with…

We report the recent results of a search for lepton-flavor-violating tau decays and a search for CP violation in tau to nu Ks pi using a large data sample accumulated with the Belle detector at the KEKB asymmetric-energy e^+e^- collider.…

We have searched for lepton-flavor-violating $\tau$ decays with a pseudoscalar meson ($\eta$, $\eta'$ {and} $\pi^0$) using a data sample of 401 fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. No…

We report results of a search for tau lepton decays strongly suppressed in the Standard Model based on the world-largest data sample accumulated with the Belle detector at the KEKB asymmetric-energy e+e- collider. The decays include: lepton…

We search for lepton-number- and baryon-number-violating decays $\tau^{-}\to\overline{p}e^{+}e^{-}$, $pe^{-}e^{-}$, $\overline{p}e^{+}\mu^{-}$, $\overline{p}e^{-}\mu^{+}$, $\overline{p}\mu^{+}\mu^{-}$, and $p\mu^{-}\mu^{-}$ using 921…