5,422 research outputs found

    Non-perturbative solutions in the electro-weak theory with tˉt\bar t t condensate and the tt-quark mass

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    We apply Bogoliubov compensation principle to the gauge electro-weak interaction to demonstrate a spontaneous generation of anomalous three-boson gauge invariant effective interaction. The non-trivial solution of compensation equations uniquely defines the form-factor of the anomalous interaction and parameters of the theory including value of gauge electro-weak coupling g(MW2)g(M_W^2) in satisfactory agreement with its experimental value. A possibility of spontaneous generation of effective four-fermion interaction of heavy quarks is also demonstrated. This interaction defines an equation for a scalar bound state of heavy quarks which serve as a substitute for the elementary scalar Higgs doublet. As a result we calculate the tt-quark mass mt=177GeVm_t\,=\,177\,GeV in satisfactory agreement with the experimental value. The results strongly support idea of tˉt\bar t\,t condensate as a source of the electro-weak symmetry breaking.Comment: 16 pages, 5 figures. arXiv admin note: substantial overlap with arXiv:1103.395

    CDF Wjj anomaly as a non-perturbative effect of the electro-weak interaction

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    The recently reported CDF excess at 120160GeV120\,-\, 160\,GeV in invariant mass distribution of jet pairs accompanying WW-boson is tentatively interpreted as a bound state of two WW decaying to quark-anti-quark pair. Non-perturbative effects of EW interaction obtained by application of Bogoliubov compensation approach lead to such bound state due to existence of anomalous three-boson gauge-invariant effective interaction. The application of this scheme gives satisfactory agreement with existing data without any adjusting parameter but the bound state mass 145GeV145\,GeV.Comment: 5 pages, 2 figure

    Local density of states at polygonal boundaries of d-wave superconductors

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    Besides the well-known existence of Andreev bound states, the zero-energy local density of states at the boundary of a d-wave superconductor strongly depends on the boundary geometry itself. In this work, we examine the influence of both a simple wedge-shaped boundary geometry and a more complicated polygonal or faceted boundary structure on the local density of states. For a wedge-shaped boundary geometry, we find oscillations of the zero-energy density of states in the corner of the wedge, depending on the opening angle of the wedge. Furthermore, we study the influence of a single Abrikosov vortex situated near a boundary, which is of either macroscopic or microscopic roughness.Comment: 10 pages, 11 figures; submitted to Phys. Rev.

    Theory of AC Josepson Effect in Superconducting Constrictions

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    We have developed a microscopic theory of ac Josephson effect in short ballistic superconducting constrictions with arbitrary electron transparency and in constrictions with diffusive electron transport. The theory is valid for arbitrary miscroscopic structure of the superconducting electrodes of the constriction. As applications of the theory we study smearing of the subgap current singularities by pair-breaking effects and also the structure of these singularities in the constrictions between the composite S/N electrodes with the proximity-induced gap in the normal layer.Comment: 11 pages, RevTex, 3 figures available on reques

    Josephson effect in superconducting constrictions with hybrid SF electrodes: peculiar properties determined by the misorientation of magnetizations

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    Josephson current in SFcFS junctions with arbitrary transparency of the constriction (c) is investigated. The emphasis is done on the analysis of the supercurrent dependencies on the misorientation angle θ\theta between the in-plane magnetizations of diffusive ferromagnetic layers (F). It is found that the current-phase relation I(ϕ)I(\phi) may be radically modified with the θ\theta variation: the harmonic I1sinϕI_{1}\sin \phi vanishes for definite value of θ\theta provided for identical orientation of the magnetizations (θ=0\theta =0) the junction is in the "π""\pi" state. The Josephson current may exhibit a nonmonotonic dependence on the misorientation angle both for realization of "0""0 " and "π""\pi " state at θ=0\theta =0. We also analyze the effect of exchange field induced enhancement of the critical current which may occur in definite range of θ\theta .Comment: 7 pages, 5 figures, submitted to JETP Letter

    Boundary resistance in magnetic multilayers

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    Quasiclassical boundary conditions for electrochemical potentials at the interface between diffusive ferromagnetic and non-magnetic metals are derived for the first time. An expression for the boundary resistance accurately accounts for the momentum conservation law as well as essential gradients of the chemical potentials. Conditions are established at which spin-asymmetry of the boundary resistance has positive or negative sign. Dependence of the spin asymmetry and the absolute value of the boundary resistance on the exchange splitting of the conduction band opens up new possibility to estimate spin polarization of the conduction band of ferromagnetic metals. Consistency of the theory is checked on existing experimental data.Comment: 8 pages, 3 figures, designed using IOPART styl

    Constructive solution of highly effective photoenergy module: development and experimental testing

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    Based on experimental study and computermodeling of working temperature influence on the efficiency of Chinese production silicon solar cells identified temperature dependence of efficiency shows the feasibility of using Chinese production Si-SC in the construction of photovoltaic thermal system, which together with the heat pump is part of a combined system for hot water supply, heating and air conditioning. Based on a detailed analysis of the working temperature influence on the efficiency of photovoltaic processes that determine the solar cells work, it has been developed the optimal construction and technological solution of hybrid solar generated module, the main feature ofwhich is the heat exchange block, designed to reduce the solar cells working temperature. The experimental testing of hybrid modules samples equipped with developed cooling system, high-voltage part of power take-off system demonstrates their reliability and high efficiency which allow to achieve the such module efficiency up to 18.5 %.На основе экспериментального исследования в комплексе с компьютерным моделированием влияния рабочей температуры на эффективность кремниевых солнечных элементов китайского производства выявлена температурная зависимость их эффективности. Температурная зависимость показывает целесообразность использования солнечных элементов китайского производства в составе фотоэлектрической тепловой системы, которая вместе с тепловым насосом является частью комбинированной системы горячего водоснабжения, отопления и кондиционирования воздуха. На основе детального анализа влияния рабочей температуры на эффективность фотоэлектрических процессов, определяющих работу солнечных элементов, было разработано оптимальное конструктивно-технологическое решение гибридного солнечного генерирующего модуля, основной особенностью которого является теплообменный блок, предназначен для снижения рабочей температуры солнечных элементов. Экспериментальные испытания образцов таких модулей, оснащенных разработанной системой охлаждения и высоковольтной системой отбора мощности, демонстрируют их надежность и высокую эффективность, позволяющие достичь КПД гибридного модуля до 18,5 %
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