New precise determination of the \tau lepton mass at KEDR detector

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, Tau0

Measurement of \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-) and \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)

The products of the electron width of the J/\psi meson and the branching fraction of its decays to the lepton pairs were measured using data from the KEDR experiment at the VEPP-4M electron-positron collider. The results are \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-)=(0.3323\pm0.0064\pm0.0048) keV, \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)=(0.3318\pm0.0052\pm0.0063) keV. Their combinations \Gamma_{ee}\times(\Gamma_{ee}+\Gamma_{\mu\mu})/\Gamma=(0.6641\pm0.0082\pm0.0100) keV, \Gamma_{ee}/\Gamma_{\mu\mu}=1.002\pm0.021\pm0.013 can be used to improve theaccuracy of the leptonic and full widths and test leptonic universality. Assuming e\mu universality and using the world average value of the lepton branching fraction, we also determine the leptonic \Gamma_{ll}=5.59\pm0.12 keV and total \Gamma=94.1\pm2.7 keV widths of the J/\psi meson.Comment: 7 pages, 6 figure

Національна доповідь про стан і перспективи розвитку освіти в Україні: монографія (До 30-річчя незалежності України)

The publication provides a comprehensive analysis of the state and development of national education over the 30 years of Ukraine’s independence, identifies current problems in education, ascertains the causes of their emergence, offers scientifically reasoned ways to modernise domestic education in the context of globalisation, European integration, innovative development, and national self-identification. Designed for legislators, state officials, education institutions leaders, teaching and academic staff, the general public, all those who seek to increase the competitiveness of Ukrainian education in the context of civilisation changes.У виданні здійснено всебічний аналіз стану і розвитку національної освіти за 30-річний період незалежності України, визначено актуальні проблеми освітньої сфери, виявлено причини їх виникнення, запропоновано науково обґрунтовані шляхи модернізації вітчизняної освіти в умовах глобалізації, європейської інтеграції, інноваційного розвитку та національної самоідентифікації. Розраховано на законодавців, державних управлінців, керівників закладів освіти, педагогічних і науково-педагогічних працівників, широку громадськість, усіх, хто прагне підвищення конкурентоспроможності української освіти в контексті цивілізаційних змін

Unusual magnetotransport properties of NbSe3_{3} single crystals at low temperature

A parallel to ($b-c$) plain field Negative magnetoresistance was found at low temperature with the magnetic field applied parallel to ($b,c$) plane of NbSe$_3$ single crystals with a thickness less than some critical value determined by the Larmor diameter. The effect observed is qualitatively explained by a size effect near the transition to the quantum limit

Elevated Exposure Rates Under Inclined Birch Trees Indicate the Occurrence of Rainfall During Radioactive Fallout from Chernobyl.

Knowledge of the mode of deposition (wet or dry) during the main fallout period following the Chernobyl accident in late April 1986 is one of the most important parameters in environmental reconstruction of the radiation dose to the thyroid from 113I following the accident. Meteorological data are available only for a small number of locations, but routine field measurements in 1997 of exposure rates in areas still contaminated by 137Cs revealed that there is a natural indicator of wet deposition. Follow-up measurements confirmed that there is a significant difference in exposure rates measured on different sides at the bases of inclined birch trees in areas of wet deposition. In such areas, the exposure rates measured on the sheltered" sides of the trees were on average 2.3+/-0.2 times those measured on the unsheltered side. In areas of dry deposition the comparable ratio was 1.01+/-0.02 for similarly inclined trees. Because birch trees are a common feature in the contaminated territories, this effect has a wide potential for use in determining whether the fallout in many areas was due to wet or dry deposition.

Interlayer tunneling spectroscopy of layered CDW materials

We have measured intrinsic tunneling spectra of charge density wave (CDW) materials NbSe$_3$ and o-TaS$_3$ in sub-micron scale mesa structures. Beyond the interband tunneling across the CDW gap, $2\Delta$, we observe intragap states at the voltage $V\approx 2\Delta/3$ which we associate with creation of the amplitude soliton. The onset of the tunneling occurs only above a threshold voltage $V_t\approx 0.1\Delta$ followed by a quasi-periodic staircase spectrum. We interpret that behavior as the CDW phase decoupling between neighboring layers via the formation of a grid of dislocation lines. In NbSe$_3$, the application of a high magnetic field (up to 27 T) yields a strong suppression of the tunneling density of states within the CDW gap indicating a possible field induced metal-insulator transition

Self-organizing carbon nitride coatings on steel from molten lead–magnesium eutectic

Based on the results of calculation and experimental studies zirconium saturated eutectic Pb–Mg alloy is recommended as liquid metal coolant in fuel elements loaded with nitride fuel. Test stand was developed and manufactured for carrying out studies of deposition of nitride and/or carbide protective coatings from molten eutectic Pb–Mg within narrow gap between coaxially arranged tubes. Pilot testing has been performed