Related papers: Rare K- (vs.) B-decays
The branching ratio of the rare decay pi0 -> e+ e- has been measured precisely, using the complete data set from the KTeV E799-II experiment at Fermilab. We observe 794 candidate pi0 -> e+ e- events using K0_L -> 3pi0 as a source of tagged…
Flavour changing neutral current decays are a very sensitive test of the standard model and its extensions. In particular the decay K -> pi nu nubar constitutes a clean way to provide constraints, independent of long distance effects.…
With their 2010-2011 data set, the LHC experiments have started their quest to observe the rare decays B0_{s/d} -> mu+ mu-. This study will provide very sensitive probes of New Physics (NP) effects. NP discovery potential lies as well in…
Soon the NA62 experiment will start looking for the rare K+ ---> pi+ nu nu bar decay. In this talk, its theoretical interests, together with those of the neutral rare decays KL ---> pi0 nu nu bar, KL ---> pi0 e+ e-, and KL ---> pi0 mu+ mu-,…
We observe 441 K_{L} -> e^{+} e^{-} e^{+} e^{-} candidate events with a background of 4.2 events and measure B(K_{L} -> e^{+} e^{-} e^{+} e^{-}) = (3.72 \pm 0.18(stat) \pm 0.23(syst)) \times 10^{-8} in the KTeV/E799II experiment at…
The work is devoted to the study of b-s anomaly decays. We evaluated branching fractions of $B\to K^\ast \mu^+\mu^-$, $B^0_s\to \phi\mu^+\mu^-$ and $B_s\to \mu^+\mu^-$ decays and compared them with available experimental data and with…
We have previously proposed a light pseudoscalar Higgs boson in the next-to-minimal supersymmetric standard model (NMSSM), the A_1^0, as a candidate to explain the HyperCP observations in Sigma^+ -> p mu^+ mu^-. In this paper we calculate…
We present an analysis of the rare exclusive $B$ decays $B\to K\nu\bar\nu$ and $B\to K^{*}\nu\bar\nu$ within the Standard Model (SM), in a model-independent manner, and in a number of new physics (NP) models. Combining new form factor…
We present a search for the rare flavor-changing neutral-current decay $B^+ \to K^+ \nu \bar{\nu}$ based on data sample of 82 fb$^{-1}$ collected with the BABAR detector at the PEP-II B-factory. Signal events are selected by examining the…
The rare $K \to \pi \nu \bar{\nu}$ decay modes and the parameter $\epsilon_K$ that measures CP violation in Kaon mixing are sensitive probes of physics beyond the standard model. In this article we provide the updated standard-model…
We report on recent developments in the phenomenology of exclusive b -> s mu^+ mu^- decays in testing the standard model and explore its borders: the benefits of the region of large dimuon invariant masses and the exploitation of the…
The transitions $B_{s,d}\rightarrow \ell^+\ell^-$ (for $\ell=e, \mu, \tau$), although extremely suppressed within the SM, are exceptionally clean channels particularly sensitive to New Physics contributions. So far only the branching ratio…
This review discusses the present experimental and theoretical status of rare flavour-changing neutral current $b$-quark decays at the begin of 2018. It includes a discussion of the experimental situation and details of the currently…
Recent BaBar results on rare B decays involving flavour-changing neutral currents or purely leptonic final states are presented. New measurements of the CP asymmetries in B -> K* gamma, B -> K*2(1430) gamma, and b -> s gamma are reported,…
This talk covers recent theoretical progress in exclusive semileptonic rare B-decays at low hadronic recoil. The efficient parametric suppression of the 1/mb corrections in this region provides opportunities to probe the Standard Model and…
We have studied the one meson radiative tau decays: tau- -> nu(tau) pi-(K-) gamma, computing the structure dependent contributions within a Lagrangian approach based on the large-N(C) limit of QCD that ensures the proper low-energy limit…
The impact of rare K decays and lepton-flavor violating processes in shedding light on physics beyond the Standard Model is reviewd. To this purpose, I first recall the formulation of the Minimal Flavor Violation hypothesis --both in the…
We calculate radiative corrections to the flavor-changing neutral current process K --> pi l+ l-, both for charged and neutral kaon decays. While the soft-photon approximation is shown to work well for the muon channels, we discuss the…
The tree-level contributions to the rare decays B+ --> pi+ nu anti-nu, B+ --> K+ nu anti-nu, and B+ --> K*+ nu anti-nu are analyzed and compared to those occurring in K+ --> pi+ nu anti-nu, D+ --> pi+ nu anti-nu, and Ds+ --> pi+ nu anti-nu.…
In the framework of SU(2) singlet down type vectorlike quark model, we present a comprehensive analysis for decays B-> X_s \gamma, B->X_sl^+l^- and B-> K\pi. As for B-> X_s\gamma, we include the QCD running from the mass of the down-type…