On the production of a lepton pair in the collision of ultrarelativistic neutral particle with nonzero magnetic moment with nuclei

Explicit formulas which describe muon pair production in reaction $\gamma\nu \to \mu^+ \mu^- \nu$ through neutrino magnetic moment are obtained and used to derive in the leading approximation cross section of muon pair production in $\nu N$-scattering due to neutrino magnetic moment. This cross section appears to be proportional to $\log^4 E_{\nu}$. Comparison with experimental data on tridents production provides an upper bound $\mu_{\nu_{\mu}} < 4*10^{-8} \mu_B$, which is approximately two orders of magnitude weaker than that from $\nu_{\mu}e$ elastic scattering data.Comment: 9 pages, 4 figures, numerical estimates are improve

Stationary mKdV hierarchy and integrability of the Dirac equations by quadratures

Using the Lie's infinitesimal method we establish that the Dirac equation in one variable is integrable by quadratures if the potential V(x) is a solution of one of the equations of the stationary mKdV hierarchy.Comment: 6 pages, LaTe

A note on a result of Liptser-Shiryaev

Given two stochastic equations with different drift terms, under very weak assumptions Liptser and Shiryaev provide the equivalence of the laws of the solutions to these equations by means of Girsanov transform. Their assumptions involve both the drift terms. We are interested in the same result but with the main assumption involving only the difference of the drift terms. Applications of our result will be presented in the finite as well as in the infinite dimensional setting.Comment: 22 pages; revised and enlarged versio

Оценка динамической составляющей работы ДВС

Briefly the technique of assessing the impact of transient modes for comprehensive indicators on the toxicity of diesel or fuel efficiency, with respect to the NRTC test cycle for off-road equipment.Кратко рассмотрена методика оценки влияния неустановившихся режимов работы на интегральные показатели дизеля по токсичности или топливной экономичности, применительно к ездовому циклу NRTC для внедорожной техники

Measurement of the Dalitz plot slope parameters for K- -> pi0 pi0 pi- decay using ISTRA+ detector

The Dalitz plot slope parameters g, h and k for the K- -> pi0 pi0 pi- decay have been measured using in-flight decays detected with the ISTRA+ setup operating in the 25 GeV negative secondary beam of the U-70 PS. About 252 K events with four-momenta measured for the pi- and four involved photons were used for the analysis. The values obtained g=0.627+/-0.004(stat)+/-0.010(syst), h=0.046+/-0.004(stat)+/-0.012(syst), k=0.001+/-0.001(stat)+/-0.002(syst) are consistent with the world averages dominated by K+ data, but have significantly smaller errors.Comment: LaTeX, 10 pages, 8 eps-figures, update of IHEP 2002-1

Structure and mechanical properties of multilayer coatings (TiAlCrY)N/ZrN

Multiperiodic nitride coatings (TiAlCrY)N/ZrN with different layer thicknesses are formed by vacuum-arc evaporation in a nitrogen atmosphere (0.2…0.6 Pa) of two targets, TiAlCrY and Zr. The targets were located along one straight line at equal distances from the perpendicular axis on which the substrates were placed. The rotation of the axis with the substrates was carried out either continuously or with a fixed delay at the evaporators. The duration of the process was chosen so that the total thickness of the coating (total thickness of the bilayers) was 10…11 μm. The effect of nitrogen pressure and modulation period on the structural-phase state, elemental composition, and mechanical properties of multilayer coatings has been studied. An increase in the partial pressure of nitrogen and, consequently, its content in the coating leads to an increase in hardness. Reducing the thickness of the layers in the coatings increases the adhesive strength of the coatings and does not have a significant effect on the microstresses in the coating.Багатоперіодичні нітридні покриття (TiAlCrY)N/ZrN з різною товщиною прошарків сформовані вакуумно-дуговим випаровуванням в азоті (0,2…0,6 Па) двох мішеней – TiAlCrY і Zr. Мішені розташовували на одній прямій на рівних відстанях від перпендикулярної осі, на якій кріпилися підкладинки. Обертання осі з підкладинками здійснювали або безперервно, або з фіксованою затримкою у випарників. Тривалість процесу вибирали так, щоб загальна товщина покриття (сумарна товщина подвійних прошарків) становила 10…11 мкм. Проаналізовано вплив тиску азоту і періоду модуляції на структурнофазовий стан, елементний склад і механічні властивості багатошарових покриттів. Збільшення парціального тиску азоту і внаслідок цього його вмісту в покритті призводить до збільшення твердості. Зменшення товщини шарів у покриттях збільшує адгезійну міцність покриттів та істотно не впливає на мікронапруження в покритті.Многопериодичные нитридные покрытия (TiAlCrY)N/ZrN с различной толщиной слоев сформированы вакуумно-дуговым испарением в среде азота (0,2…0,6 Па) двух мишеней – TiAlCrY и Zr. Мишени располагали вдоль одной прямой на равных расстояниях от перпендикулярной оси, на которой располагали подложки. Вращение оси с подложками осуществляли либо непрерывно, либо с фиксированной задержкой у испарителей. Длительность процесса выбирали так, чтобы общая толщина покрытия (суммарная толщина бислоев) составляла 10…11 мкм. Проанализировано влияние давления азота и периода модуляции на структурно-фазовое состояние, элементный состав и механические свойства многослойных покрытий. Увеличение парциального давления азота и вследствие этого – его содержания в покрытии приводит к увеличению твердости. Уменьшение толщины слоев в покрытиях увеличивает адгезионную прочность покрытий и не оказывает существенного влияния на микронапряжения в покрытии

Low-Luminosity Accretion in Black Hole X-ray Binaries and Active Galactic Nuclei

At luminosities below a few percent of Eddington, accreting black holes switch to a hard spectral state which is very different from the soft blackbody-like spectral state that is found at higher luminosities. The hard state is well-described by a two-temperature, optically thin, geometrically thick, advection-dominated accretion flow (ADAF) in which the ions are extremely hot (up to $10^{12}$ K near the black hole), the electrons are also hot ($\sim10^{9-10.5}$ K), and thermal Comptonization dominates the X-ray emission. The radiative efficiency of an ADAF decreases rapidly with decreasing mass accretion rate, becoming extremely low when a source reaches quiescence. ADAFs are expected to have strong outflows, which may explain why relativistic jets are often inferred from the radio emission of these sources. It has been suggested that most of the X-ray emission also comes from a jet, but this is less well established.Comment: To appear in "From X-ray Binaries to Quasars: Black Hole Accretion on All Mass Scales" edited by T. Maccarone, R. Fender, L. Ho, to be published as a special edition of "Astrophysics and Space Science" by Kluwe

Current Status of Simulations

As the title suggests, the purpose of this chapter is to review the current status of numerical simulations of black hole accretion disks. This chapter focuses exclusively on global simulations of the accretion process within a few tens of gravitational radii of the black hole. Most of the simulations discussed are performed using general relativistic magnetohydrodynamic (MHD) schemes, although some mention is made of Newtonian radiation MHD simulations and smoothed particle hydrodynamics. The goal is to convey some of the exciting work that has been going on in the past few years and provide some speculation on future directions.Comment: 15 pages, 14 figures, to appear in the proceedings of the ISSI-Bern workshop on "The Physics of Accretion onto Black Holes" (8-12 October 2012

Pion and sigma meson properties in a relativistic quark model

A variety of strong and electroweak interaction properties of the pion and the light scalar sigma meson are computed in a relativistic quark model. Under the assumption that the resulting coupling of these mesons to the constituent quarks is identical, the sigma meson mass is determined as M_sigma=385.4 MeV. We discuss in detail the gauging of the non-local meson-quark interaction and calculate the electromagnetic form factor of the pion and the form factors of the pi(0) -> gamma gamma and sigma -> gamma gamma processes. We obtain explicit expressions for the relevant form factors and evaluate the leading and next-to-leading orders for large Euclidean photon virtualities. Turning to the decay properties of the sigma we determine the width of the electromagnetic sigma -> gamma gamma transition and discuss the strong decay sigma -> pi pi. In a final step we compute the nonleptonic decays D -> sigma pi and B -> sigma pi relevant for the possible observation of the sigma meson. All our results are compared to available experimental data and to results of other theoretical studies.Comment: 46 page

High statistics study of the K- -> pi0 e- nu decay

The decay K- -> pi0 e- nu has been studied using in-flight decays detected with the "ISTRA+" spectrometer working at the 25 GeV negative secondary beam of the U-70 PS. About 550K events were used for the analysis. The lambda+ parameter of the vector form-factor has been measured: lambda+ = 0.0286 +- 0.0008 (stat) +- 0.0006(syst). The limits on the possible tensor and scalar couplings have been obtained: f(T)/f+(0)=0.021 +0.064 -0.075 (stat) +- 0.026(syst) ; f(S)/f+(0)=0.002 +0.020 -0.022 (stat) +- 0.003(syst)Comment: LaTeX-2e, epsfig.sty, 10 pages, 7 figures in EPS forma