[en] We review results from CLEO, LEP and the Tevatron experiments on rare decays of B hadrons to final states including charged leptons

[en] The decay rate of Higgs Scalar boson into lepton and anti-lepton is calculated

[en] If any neutrinos have mass the reaction π⁰→γanti γ is allowed. With the forthcoming generation of machines this could provide a practical means for finding limits on neutrino masses. (Auth.)

[en] We show prospects for research of invisible decays of B meson in a sample of about 470 millions BB pairs recorded with the BABAR detector at the SLAC PEP-II B factory. The Standard Model predictions for a B decay with completely invisible final products (or with a single photon as detectable particle) are far from the current experimental sensitivities but several New Physics Models predict significant enhancements on the branching ratio of these decays. The analysis technique consists in the reconstruction of a semileptonic B decay on one side and in the search of missing energy or missing energy plus one photon in the recoil. We will describe the search techniques and provide the expected sensitivities for these decays.

[en] This discussion is limited to decays of charged and neutral K mesons. The present experimental situations regarding K → lν, K → πlν, K → ππγ, K⁰/sub L/ → μ⁺μ^-, and K⁺ → π⁺e⁺e^- are reviewed

[en] We briefly review the discovery of the first b-flavored particle, the B-meson, and derive limits for its mass. The decay properties of the B-meson have been studied at CESR with the CUSB detector. The decay B → eνX has been observed as well as copious K-meson production. Both the shape of the electron spectrum and the K-meson signal imply dominance of the (bc)W coupling relative to the (bu)W coupling

[en] We have re-evaluated the results of the neutron lifetime experiment based on storage of decay protons in a Penning trap. Combining improved statistical treatment of the data with precise measurements of the magnetic-field distribution in the trap, we arrive at a revised value τ_n = 889.2 ± 4.8 s. (orig.)

[en] We review the idea of leptonic unitary triangles and extend the concept of the recently proposed unitary boomerangs to the lepton sector. Using a convenient parametrization of the lepton mixing, we provide approximate expressions for the side lengths and the angles of the six different triangles and give examples of leptonic unitary boomerangs. Possible applications of the leptonic unitary boomerangs are also briefly discussed.

[en] Here, we report the results of a search for the rare, purely leptonic decay B ^–→μ ^–¯νμ performed with a 711 fb ^–1 data sample that contains 772 × 10 ⁶ B¯B pairs, collected near the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e ⁺e ^– collider. The signal events are selected based on the presence of a high momentum muon and the topology of the rest of the event showing properties of a generic B-meson decay, as well as the missing energy and momentum being consistent with the hypothesis of a neutrino from the signal decay. We find a 2.4 standard deviation excess above background including systematic uncertainties, which corresponds to a branching fraction of B(B ^–→μ ^–¯νμ) = (6.46 ± 2.22 ± 1.60) × 10 ^–7 or a frequentist 90% confidence level interval on the B ^–→μ ^–¯νμ branching fraction of [2.9,10.7] × 10 ^–7. Authors:

No abstract available