X,γ,β–spectrometric investigations of Chernobyl “hot particles” nuclide composition

Results of investigation of the radionuclide composition of “hot particles” from Chernobyl “Shelter” Object are discussed. An estimate of radionuclide activity of radioactive pollution levels for some premises of “Shelter” is performed

Multiple (inverse) binomial sums of arbitrary weight and depth and the all-order epsilon-expansion of generalized hypergeometric functions with one half-integer value of parameter

We continue the study of the construction of analytical coefficients of the epsilon-expansion of hypergeometric functions and their connection with Feynman diagrams. In this paper, we show the following results: Theorem A: The multiple (inverse) binomial sums of arbitrary weight and depth (see Eq. (1.1)) are expressible in terms of Remiddi-Vermaseren functions. Theorem B: The epsilon expansion of a hypergeometric function with one half-integer value of parameter (see Eq. (1.2)) is expressible in terms of the harmonic polylogarithms of Remiddi and Vermaseren with coefficients that are ratios of polynomials. Some extra materials are available via the www at this http://theor.jinr.ru/~kalmykov/hypergeom/hyper.htmlComment: 24 pages, latex with amsmath and JHEP3.cls; v2: some typos corrected and a few references added; v3: few references added

de Sitter Vacua in String Theory

We outline the construction of metastable de Sitter vacua of type IIB string theory. Our starting point is highly warped IIB compactifications with nontrivial NS and RR three-form fluxes. By incorporating known corrections to the superpotential from Euclidean D-brane instantons or gaugino condensation, one can make models with all moduli fixed, yielding a supersymmetric AdS vacuum. Inclusion of a small number of anti-D3 branes in the resulting warped geometry allows one to uplift the AdS minimum and make it a metastable de Sitter ground state. The lifetime of our metastable de Sitter vacua is much greater than the cosmological timescale of 10^10 years. We also prove, under certain conditions, that the lifetime of dS space in string theory will always be shorter than the recurrence time.Comment: 12 pages, 2 figs, added comments on the thin wall approximation to tunnelin

Leading order analysis of neutrino induced dimuon events in the CHORUS experiment

We present a leading order QCD analysis of a sample of neutrino induced charged-current events with two muons in the final state originating in the lead-scintillating fibre calorimeter of the CHORUS detector. The results are based on a sample of 8910 neutrino and 430 antineutrino induced opposite-sign dimuon events collected during the exposure of the detector to the CERN Wide Band Neutrino Beam between 1995 and 1998. % with $E_{\mu 1},E_{\mu 2} > 5$ GeV and $Q^2 > 3$ GeV$^2$ collected %between 1995 and 1998. The analysis yields a value of the charm quark mass of \mc = (1.26\pm 0.16 \pm 0.09) \GeVcc and a value of the ratio of the strange to non-strange sea in the nucleon of $\kappa = 0.33 \pm 0.05 \pm 0.05$, improving the results obtained in similar analyses by previous experiments.Comment: Submitted to Nuclear Physics

Associated Charm Production in Neutrino-Nucleus Interactions

In this paper a search for associated charm production both in neutral and charged current $\nu$-nucleus interactions is presented. The improvement of automatic scanning systems in the {CHORUS} experiment allows an efficient search to be performed in emulsion for short-lived particles. Hence a search for rare processes, like the associated charm production, becomes possible through the observation of the double charm-decay topology with a very low background. About 130,000 $\nu$ interactions located in the emulsion target have been analysed. Three events with two charm decays have been observed in the neutral-current sample with an estimated background of 0.18$\pm$0.05. The relative rate of the associated charm cross-section in deep inelastic $\nu$ interactions, $\sigma(c\bar{c}\nu)/\sigma_\mathrm{NC}^\mathrm{DIS}= (3.62^{+2.95}_{-2.42}({stat})\pm 0.54({syst}))\times 10^{-3}$ has been measured. One event with two charm decays has been observed in charged-current $\nu_\mu$ interactions with an estimated background of 0.18$\pm$0.06 and the upper limit on associated charm production in charged-current interactions at 90% C.L. has been found to be $\sigma (c\bar{c} \mu^-)/\sigma_\mathrm{CC} < 9.69 \times 10^{-4}$.Comment: 10 pages, 4 figure

Influence of working gas pulse injection and fluctuations of the magnetic field on the runaway electrons dynamics in Uragan-3M

Generation of runaway electrons in fusion experiments can drive to serious damage of plasma devices components. Injection of gas with a large mass number decreases the generation processes. Also, magnetic perturbations decrease generation of runaway electrons by increasing the loss rate. We investigated the influence of working gas pulse injection and natural fluctuations of the magnetic confining field on runaway electrons dynamics. The interaction of runaway electrons with an Alfven wave in plasma is noted.Генерація утікаючих електронів в експериментах синтезу може привести до серйозного пошкодження компонентів плазмових пристроїв. Інжекція важкого газу зменшує процеси генерації. Магнітні збурення також пригнічують генерацію утікаючих електронів за рахунок збільшення швидкості втрат. Досліджено вплив імпульсного напуску газу і природних флуктуацій утримуючого магнітного поля на динаміку утікаючих електронів. Відзначено взаємодія утікаючих електронів з альфвеновською хвилею в плазмі.Генерация убегающих электронов в экспериментах синтеза может привести к серьезному повреждению компонентов плазменных устройств. Инжекция тяжелого газа уменьшает процессы генерации. Магнитные возмущения также подавляют генерацию убегающих электронов за счет увеличения скорости потерь. Исследовалось влияние импульсного напускающего газа и естественных флуктуаций удерживающего магнитного поля на динамику убегающих электронов. Отмечено взаимодействие убегающих электронов с альфвеновской волной в плазме

Amplification of the runaway electrons flow in the Uragan-3М torsatron

In this work the results of amplification of the runaway electrons flow and interaction runaway electrons with RF-heating wave on the Uragan-3M torsatron are presented. Results described in the article confirm using runaway electrons for gas breakdown. The results allow making some recommendations for using of self-created flows of accelerated particles for stimulation of gas breakdown.Наведено результати експериментальних досліджень щодо посилення потоку утікаючих електронів, а також взаємодії потоку утікаючих електронів з електромагнітним полем хвилі, що збуджується високочастотним імпульсом у торсатроні Ураган-3М. Отримані результати підтверджують можливість пробою газу утікаючими електронами. Це дозволяє представити ряд рекомендацій по використанню потоків прискорених частинок для стимуляції високочастотного пробою.Приведены результаты экспериментальных исследований по усилению потока убегающих электронов, а также взаимодействию потока убегающих электронов с электромагнитным полем волны, возбуждаемой высокочастотным импульсом в торсатроне Ураган-3М. Полученные результаты подтверждают возможность пробоя газа убегающими электронами. Это позволяет представить ряд рекомендаций по использованию самопроизвольно формирующихся потоков ускоренных частиц для стимуляции высокочастотного пробоя

Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV

Peer reviewe

Search for long-lived doubly charged Higgs bosons in p(p)over-bar collisions at root s=1.96 TeV

We present a search for long-lived doubly charged Higgs bosons (H+/-+/-), with signatures of high ionization energy loss and muonlike penetration. We use 292 pb(-1) of data collected in p (p) over bar collisions at root s=1.96 TeV by the CDF II detector at the Fermilab Tevatron. Observing no evidence of long-lived doubly charged particle production, we exclude H-L(+/-+/-) and H-R(+/-+/-) bosons with masses below 133 GeV/c(2) and 109 GeV/c(2), respectively. In the degenerate case we exclude H+/-+/- mass below 146 GeV/c(2). All limits are quoted at the 95% confidence level

Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

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