Related papers: Purely Leptonic B decays at High Luminosity e+e- B…

Rare lepton decays of the B(s), D and K mesons are sensitive probes of New Physics. In particular, the search for the decays $B^0_(s) -> \mu^+ \mu^-$ provides information on the presence of new (pseudo-)scalar particles. LHCb is well suited…

The purely leptonic decays D -> e nu and Ds -> e nu, for which no experimental limits exist, are highly suppressed in the Standard Model. Mere observation of these decays at the B factories BELLE/BaBar or forthcoming CLEO-c would be a clear…

We present a complete study of R-parity violating supersymmetric effects in thirteen exclusive and inclusive semi-leptonic $b \to (s,d) \nu \bar{\nu}$ decays, including $B^+_u\to K^{(*)+}\nu\bar{\nu}$, $B^0_d\to K^{(*)0}\nu\bar{\nu}$,…

We will present the most recent results on leptonic B decays $B^{\pm(0)} \to K^{* \pm (0)} \nu \bar{\nu}$ and $B^{\pm} \to \mu^{\pm} \nu$, based on the data collected by the BaBar detector at PEP-II, an asymmetric $e^+ e^-$ collider at the…

Leptonic decays of $B$-mesons are theoretically very clean probes for testing the Standard Model (SM) and possible physics beyond it. Amongst the various leptonic decays of the $B$-meson, the pure dileptonic decay $B \to \ell^+ \ell^-$ is…

We present a search for the decays B+ -> mu+ nu_mu and B+ -> e+ nu_e in a 253 fb-1 data sample collected at the \Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy B factory. We find no significant evidence for a…

In this article we show that the recently observed enhanced semi-leptonic and leptonic decay rates of the B meson into \tau \nu modes can be explained within the frame work of R-parity violating (RPV) MSSM. In particular, RPV contributions…

We review recent results from the BABAR and Belle experiments on rare electroweak B-meson decays, with emphasis on those occurring through flavor changing neutral current interactions of the type b -> s l l. The recent results include…

The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility, Belle, at the Japanese KEK laboratory. The main operation of SuperKEKB has started in March 2019, and…

We study the decays Bu -> l nu and Bc -> l nu in the context of the Minimal Supersymmetric Standard Model (MSSM) with explicit R parity violation. We analyse the correlation between the two decays and show that branching ratios (BRs) for Bc…

Rare radiative, leptonic and semileptonic B meson decays are valuable probes of physics beyond the Standard Model. This talk reviews the sensitivity to new physics of observables related to two rare B decays to be measured in the near…

We have searched for the leptonic and radiative leptonic B decays, B^+ -> mu^+ nu, B^+ -> e^+ nu gamma and B^+ -> mu^+ nu gamma. Using a 140 fb^{-1} data sample collected with the Belle detector at the KEKB asymmetric e^+ e^- collider, we…

This paper reviews the status of searches and measurements of Bu leptonic decays, concentrating on the most recent results obtained at B-factories. We will describe studies of decays of the type B+ -> ell+ nu and B+ -> ell+ nu gamma.

We put constraints on several products of R-parity violating lambda lambda' and lambda' lambda' type couplings from leptonic and semileptonic tau, B_d and B_s decays. Most of them are one to two orders of magnitude better than the existing…

We study the decay B --> K l^+ l^- for l = e,mu,tau with a softly recoiling kaon, that is, for high dilepton invariant masses sqrt{q^2} of the order of the b-quark mass. This kinematic region can be treated within an operator product…

We consider the exclusive flavor changing neutral current processes B -> M \nu \bar{\nu} (M= \pi, K, \rho, K^*) in the leptophobic Z^\prime model, in which the charged leptons do not couple to the extra Z^\prime boson. We find that these…

We present a review of the searches for very rare decays to muonic final states performed at LHCb using 1.0 fb-1 of pp collisions at 7 TeV centre of mass energy. Flavour changing neutral current processes, such as B->mumu and B->mumumumu…

Investigating leptonic decays of pi^-, K^-, B^-, pi^0, K_L^0, B_s^0 we present new bounds on some products of two R-parity violating coupling constants. For mesons of a similar structure but so far poor experimental data we give the…

We present the recent BaBar searches for the leptonic decay B+ --> tau+ nu and for the rare decay B --> K(*) nu nubar, using a data sample of about 470 x 10^6 BB pairs. Both searches use a technique in which one B meson is hadronically…

The main physics goals of a high luminosity e+e- flavor factory are discussed, including the possibilities to perform detailed studies of the CKM mechanism of quark mixing, and constrain virtual Higgs and non-standard model particle…