[en] The status of our work on heavy meson production is presented for charmonium. In order to reach a homogeneous understanding of heavy meson production in different hadronic processes, our aim has been to perform a complete microscopic description of the relevant physical processes involved. These include the production of an initially strongly localized cc-bar that evolves in time while simultaneously taking account of its interaction with surrounding hadronic matter, such as transitions mixing different charmonium states caused by the gluonic fields from the scattering hadrons. The time evolution of charmonium, including these processes, can be treated analytically in a quantum mechanical picture. The results on J/Ψ production are presented and compared with the experimental data. (author)

[en] The paper reviews the latest progress on the observation of new heavy mesons and the non-rare decays of heavy mesons

[en] Current neutrino experiments at accelerators, and recent results, are reviewed. Accelerator experiments are today investigating fundamental properties of the neutrinos and of the Standard Model. Neutrino masses are probed, through the oscillation phenomenon, in the domain of squared mass differences Δm² above 0.1 eV². Six experiments are currently producing results: CHORUS, DONUT, KARMEN, LSND, NOMAD and NUTEV. Their features are critically examined, and the neutrino oscillation result claimed by LSND is confronted of the new results from KARMEN

[en] We discuss the issue of duality violations in hadronic tau decay. After introducing a physically motivated ansatz for duality violations, we estimate their possible size by fitting this ansatz to the tau experimental data provided by the ALEPH Collaboration. Our conclusion is that these data do not exclude significant duality violations in tau decay. This may imply an additional systematic error in the value of α_s(m_τ), extracted from tau decay, as large as δα_s(m_τ)∼0.003-0.010.

[en] Decays of mesons with high spins ( J/sup P/ = 2⁺, 4⁺, 6⁺, 8⁺)= are studied in the virton-quark model assuming that the mesons are two-quark systems. It is shown that in order to describe the existing experimental data it is necessary to assume that the states of the qq-bar system with orbital angular momenta l = J-1 and l = J+1 are roughly of the same order of magnitude

[en] We report an analysis of charmless hadronic decays of neutral B mesons to the final state K_S⁰K^±π ^#-+#, using a data sample of (465 ± 5) x 10⁶ B(bar B) events collected with the BABAR detector at the Υ(4S) resonance. We observe an excess of signal events with a significance of 5.2 standard deviations including systematic uncertainties and measure the branching fraction to be Β(B⁰ → K_S⁰K^±π^#-+#) = (3.2 ± 0.5 ± 0.3) x 10^-6, where the uncertainties are statistical and systematic, respectively.

[en] The theoretical calculation for pseudo-scalars hadronic decays K → πa is reviewed. While one-loop penguin contributions are usually considered, tree-level processes have most often been overlooked in literature. Following the Lepage-Brodsky approach the tree-level contribution to the charged and neutral pseudo-scalar decay in ALP is estimated. Assuming generic ALP couplings to SM fermions, the latest NA62/E949 results for the K${}^{+}$ → π${}^{+}$a decay and the present/future KOTO results for the K${}_L^0$ → π${}^0$a decay are used to provide updated bounds on the ALP-fermion Lagrangian sector. Finally, the interplay between the tree-level and one-loop contributions is investigated.

[en] A search for hadronic charmless decays of B hadrons has been performed with the ALEPH detector at LEP. Four candidates have been observed in the h⁺h^-channel. The probability that these four candidates come from background was estimated to be less than 10^-6. The branching ratio of a B meson into two oppositely charged hadrons was measured to be Br(B → h⁺h^-) (1.7^+1.0_-0.7±0.2) x 10^-5. The relative branching fraction Br(B_d(s)⁰ → π⁺π^-(K^-))/Br(B_d(s)⁰ → h⁺h^-) was estimated to be (1.^+0.0_-0.3^+0.0_-0.1). A number of other decay channels of neutral or charged B mesons into charged pions have also been studied. Upper limits on the branching ratios have been computed. (orig.)

[en] The situation with regard to the widths and asymmetries in the decays of kaons into three pions is discussed. Allowance for the finite size of the decaying kaon can lead to corrections of the order of a few percent in the asymmetries of the decays, exceeding the Coulomb corrections, which should be noticeable in the case of the more accurate experimental data expected at kaon factories. 9 refs

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