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The product of the electronic width of the ψ(2S) meson and the branching fraction of its decay to the muon pair was measured in the e+e−→ψ(2S)→μ+μ− process using nine data sets corresponding to an integrated luminosity of about 6.5 pb−1 collected with the KEDR detector at the VEPP-4M electron–positron collider:Γee×Bμμ=19.3±0.3±0.5eV. Adding the previous KEDR results on hadronic and leptonic channels, the values of the ψ(2S) electronic width were obtained under two assumptions: either with the assumption of lepton universalityΓee=2.279±0.015±0.042keV or without it, summing up hadronic and three independent leptonic channelsΓee=2.282±0.015±0.042keV. Keywords: ψ(2S) meson, Leptonic width, Branching fraction

New measurements of ψ ( 2 S ) , ψ ( 3770 ) and D meson masses are presented. The results of the scans performed were used for determination of the products Γ e e × Γ e e / Γ for J / ψ and Γ e e × Γ μ μ / Γ for ψ ( 2 S ) .

The status of the experiment on the precise $\tau$ lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the $\tau^+\tau^-$ cross section behaviour around the production threshold. The preliminary result based on 6.7 pb$^{-1}$ of data is $m_{\tau}=1776.80^{+0.25}_{-0.23} \pm 0.15$ MeV. Using 0.8 pb$^{-1}$ of data collected at the $\psi'$ peak the preliminary result is also obtained: $\Gamma_{ee}B_{\tau\tau}(\psi') = 7.2 \pm 2.1$ eV., Comment: 6 pages, 8 figures; The 9th International Workshop on Tau-Lepton Physics, Tau06

The status of the experiment on the precise τ lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the τ + τ − cross section behavior around the production threshold. The preliminary result based on 15.2 pb −1 of data is m τ = 1776.69 −0.19 +0.17 ± 0.15 MeV .

High precision mass measurements in $\Psi$ and $\Upsilon$ families performed in 1980-1984 at the VEPP-4 collider with OLYA and MD-1 detectors are revisited. The corrections for the new value of the electron mass are presented. The effect of the updated radiative corrections has been calculated for the $J/\Psi(1S)$ and $\Psi(2S)$ mass measurements.

Recent USSR legislation governing the Soviet exclusive economic zone is reviewed. Soviet municipal legislation on pollution control is compared against the provisions of the 1982 Law of the Sea (LOS) Convention, and points of noncompliance are identified. The method stipulated in Soviet legislation for calculating losses caused by pollution is highlighted as an area of special concern.

This review considers the factors which influence the exciton behavior at the semiconductor surface and, consequently, are revealed through excitonic optical spectra. The basic knowledge of excitons in semiconductors is first presented. The experimental exciton reflectance spectra of CdS and CdSe crystals are discussed followed by an analysis of the results which make use of the near-surface “dead-layer” model. In particular, the effect of the electron irradiation on the exciton reflectance lineshape and exciton photoluminescence is considered with reference to the physical factors which control optical spectra. Various mechanisms of localization of excitons in a semiconductor surface region are presented. Relevant experiments on low-temperature photoluminescence and reflectance are discussed. Finally, the effect on the exciton reflectance of the electric field of the space-charge layer is considered in detail.

A new mechanism for the Fermi-level pinning at semiconductor surfaces is proposed. It is based on consideration of electrically active surface chemical reactions which create or destroy the surface charge. Mutual neutralization of the charging and discharging reactions leads to the Fermi-level pinning. The compensation of charge flows is caused by inversion of the conductivity type at the surface. In this case the Fermi-Level is pinned near mid-gap. The normal and anomalous kinetics of surface-barrier formation for adsorption of O, S, Cl, Al, Au, Ag, In, Ga, Mn and Sb on GaAs(110) surface are interpreted in a two-mode chemisorption model Un nouveau mecanisme de l'accrochage («pinning») du niveau de Fermi a la surface des semiconducteurs est propose. Il est base sur l'examen de reactions chimiques electriquement actives qui creeent ou detruisent la charge de surface. La neutralisation mutuelle des reactions de charge et decharge conduit a l'accrochage du niveau Fermi. La compensation des ecoulements de charges est due a l'inversion du type de conductivite en surface. Dans ce cas le niveau de Fermi est accroche au milieu de la bande interdite. Les cinetiques normales et anormales de formation de barrieres de surface lors de l'adsorption de O, S, Cl, Al, Au, Ag, In, Ga, Mn et Sb sur la surface de GaAs (110) sont interpretees suivant deux modes de chimisorption

This article looks at how in various parts of the seas and oceans the marine environment has been subjected to pollution, the vulnerability to which also varies depending on oceanographical and ecological conditions. Consequently, the international norms and standards intended for universal application with regard to preventing pollution of the sea from ships may prove to be inadequate to protect the marine environment of individual areas of the oceans.

Effect of the short-range near-surface exciton potential on the interference spectra of thin crystals is studied theoretically. The potential modeled by a right-angled well or step leads to a strong perturbation both of the Fabry-Perot structure and the one due to the interference of the additional waves. Several effects are discussed. The most interesting one is the correlation between the localization of the exciton in the near-surface potential well and the change by π of the exciton-wave phase. The surface exciton is displayed by a strong maximum in reflection spectra, and the phase change results in the almost entire quenching of the additional interference structure.

The analytical and numerical investigations of trajectories of the probe beam electrons in the two dimensional wakefield, excited in plasma by a dense bunch of relativistic electrons with Gauss longitudinal and transverse distribution of density is carried out. On the basis of calculations of probe beam deviations, the diagnostic instrument is developed for parameters of experiments conducted in NSC KIPT. The diagnostic instruments consist of an electron gun forming the electron beam with energy 10 KeV, current 10 /spl mu/A and diameter 2 mm which passes through the chamber of interaction and falls on a collector of diameter 10 mm. A collector (screen) is placed in front of the first plate of a microchannel amplifier which consists of three microchannel plates (MCP) with sizes 20-30 mm. The voltage of 3 kV was applied to each plate. Total amplification of MCP amplifier is 10/sup 4/-10/sup 5/ in dependence on quantity of particles, falling on the first plate. As a result the deviations of probe beam by excited wakefield the electrons fall on the first plate of the amplifier and are registered by the anode of the amplifier, located behind the third plates. Calculated probe beam deviations and obtained amplification of MCP amplifier permit investigation of the electrical wakefields, excited by the sequence of relativistic bunches (number of particles in bunch is 2/spl middot/10/sup 9/, energy is 14 MeV) in plasma of density 10/sup 11/-10/sup 13/ cm/sup -3/. The maximal value of the fields registered by such a technique is not less 2 kV/cm.