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

CP violation in $\tau\to K_S \pi\nu_\tau$ decays has attracted a lot of attention recently, due to the BaBar anomaly in the corresponding rate asymmetry. Within an effective field theory formalism, only extreme fine-tuning would allow to…

We update the single-coupling bounds on R-parity violating supersymmetry using the most up to date data as of October 2009. In addition to the data listed in the 2009 Review of Particle Properties, we utilize a new determination of the weak…

It was recently claimed that single stop production at the Tevatron, occurring via R-parity (and baryon number) violating couplings, could lead to observable signals. In this talk I present some results of a work in progress, showing that…

It is experimentally observed that ratios of branching fractions for semitauonic and semileptonic $B$ decays, known as the $R(D^{(*)})$, are higher than Standard Model (SM) predictions. The $B \to \bar{D}^{(*)} \tau^{+} \nu_{\tau}$ decays,…

Using $(771.6 \pm 10.6) \times 10^6$ $B\bar{B}$ meson pairs recorded by the Belle experiment at the KEKB $e^+ e^-$ collider, we report the branching fractions $\mathcal{B}(\bar{B}^0 \to D^{*+} \pi^-) = (2.62 \pm 0.02 \pm 0.09)\times…

We present a study of the decay tau- -> K_S pi- nu_tau using a 351 fb^-1 data sample collected with the Belle detector. The analysis is based on 53110 lepton-tagged signal events. The measured branching fraction B(tau- -> K_S pi-…

We compute B->K eta' branching ratio using perturbative QCD approach. We show that a triangular relation among amplitudes for B^0->K^0 pi^0, B^0->K^0 eta, B^0->K^0 eta' receives large corrections from SU(3) breaking effects. If experimental…

We have searched for decays that violate both lepton and baryon number using data collected by the Belle detector at the KEKB asymmetric e^+e^- collider. No signals are found in tau^- -> \bar{p} gamma, tau^- -> \bar{p} pi^0, tau^- ->…

The rare decays B_s -> \mu^+\mu^- and B -> K^{(*)}\mu^+\mu^- are sensitive to new particles and couplings via their interferences with the standard model contributions. Recently, the upper bound on B(B_s -> \mu^+\mu^-) has been improved…

We reconstruct B0bar -> D_s^-D^+ decays using a sample of 275 million BBbar pairs recorded by the Belle experiment, and we measure the branching fraction to be [7.42 +- 0.23(stat) +- 1.36(syst)] x 10^(-3). We also search for the related…

We present the first evidence of the decay B- --> tau- nu_tau-bar using 414 fb^-1 of data collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. Events are tagged by fully reconstructing…

Measurements of the branching ratios of $B \to D^{(*)}\tau\bar\nu/B \to D^{(*)}\ell\bar\nu$ and $B_c\to J/\psi\, \tau\bar\nu/B_c\to J/\psi\, \ell\bar\nu$ by the BaBar, Belle and LHCb collaborations consistently point towards an abundance of…

We report a measurement of the branching fraction of B^+ -> tau^+ nu_tau decays using a data sample of 772 x 10^6 BBbar pairs, collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We…

We report on a study of the branching fractions for the exclusive charmless semileptonic B decay modes B to pi+ l nu, B to pi0 l nu, B to rho+ l nu, B to rho0 l nu and B to omega l nu, using events tagged by fully reconstructing one of the…

Using 13.53/fb of CLEO data, we have measured the ratios of the branching fractions R+(e) = BF(D+ --> K*0bar e+ nu_e) / BF(D+ --> K- pi+ pi+), R+(mu) = BF(D+ --> K*0bar mu+ nu_mu) / BF(D+ --> K- pi+ pi+) and the combined branching fraction…

Recently, the Belle collaboration reported the first measurements of the $\tau^- \to\nu_{\tau}\pi^-e^+e^-$ branching fraction and the spectrum of the pion-dielectron system. In an analysis previous to Belle's results, we evaluated this…

The recent measurements of $B_s^0 \to \mu\bar{\mu}$ decay candidates at the LHC consistent with the standard model rate, and the improving upper limits for $B_d^0 \to \mu\bar{\mu}$ can strongly constrain beyond the standard model physics.…

The recently measured B -> tau nu branching ratio allows to test the Standard Model by probing virtual effects of new heavy particles, such as a charged Higgs boson. The accuracy of the test is currently limited by the experimental error on…

We have searched for neutrinoless $\tau$ lepton decays into $\ell$ and $V^0$, where $\ell$ stands for an electron or muon, and $V^0$ for a vector meson ($\phi$, $\omega$, $K^{*0}$ or $\bar{K}^{*0}$), using 543 fb$^{-1}$ of data collected…

We consider one-loop corrections to partial widths of the $Z$ induced by supersymmetric Yukawa interactions that violate $R$-parity. The precise experimental values of the leptonic $Z$ partial widths bound these Yukawa couplings, with the…