77 research outputs found

    P- and T-violation Tests with Polarized Resonance Neutrons

    Get PDF
    The enhancements of CP-violating effects in resonance neutron transmissionthrough polarized targets are studied for 2 possible versions of experiment. The importance is stressed of error analysis and of pseudomagnetic effects' compensation.Comment: 11 pages, LaTeX + 4 PostScript figure

    Distinctive Features of the Phase Composition of Porous TiNi-based Alloys Obtained by Reaction and Diffusion Sintering

    Get PDF
    The present article is concerned with questions of reaction and diffusion sintering of porous shape-memory TiNi-based alloys. The comparative analysis of structural features of the porous alloys obtained by diffusion sintering of TiNi powder and reaction sintering of Ti and Ni powders was conducted. It is observed that the main feature of structure of the porous alloys is related to fraction of the TiNi phase which occupies about 90 vol.% at diffusion sintering, and 20÷50 % of the total volume of multiphase alloy for reaction sintering. The mechanisms of the structure formation on the solid phase and liquid phase sintering stages of these methods were considered. The role of Ti2Ni phase during sintering was disclosed. The Ti2Ni phase not only provides the necessary quality of sintering, activates recrystallization processes for diffusion sintering, modifies the phase composition of the sintered specimen for reaction sintering, but also participates in the formation of the TiNi phase, increasing its fraction

    Crystallization Features of Porous TiNi Made by SHS

    Get PDF
    The surface layers and fracture surfaces of porous titanium nickelide obtained by self-propagating high temperature synthesis (SHS) in a flow reactor in an argon atmosphere are studied by SEM and energy dispersive analysis. It is alleged that primary pores 5–15 µ in size and the related granular layer are formed due to segregation and capillary force effect during peritectic crystallization of some porous alloy areas. Coarsening and deformation of pores, as well as migration and growth of granular layers, is caused by reaction gases. Carbon and oxygen impurities present in the reaction gases and the protective atmosphere penetrate into the melt film on the pore surface to form strong and corrosion-resistant nanostructured layers of intermetallic carbides, nitrides and oxides

    Structure and Application of ATDP Suite for Electronic System States Detection and Evolution Operator Restoration

    No full text
    Structure and peculiarities of the Adaptive Testing Data Processing software Suite (ATDP Suite) are presented. It is applied for dynamic characteristics restoration from experimental time series of nonlinear and unstable electronic system. Basic methods realized in ATDP Suite are demonstrated. Application of ATDP Suite for electromagnetic tests of microwave receivers demonstrated the possibility to analyze and interpret the dynamic characteristics of complex nonlinear system.Представлены структура и особенности программного пакета адаптивной тестирующей обработки данных (ATDP Suite). Он применен к восстановлению динамических характеристик из экспериментальных временных рядов нелинейной и нестабильной электронной системы. Продемонстрированы основные методы, реализованные в ATDP Suite. Применение ATDP Suite для электромагнитного тестирования СВЧ приемников показало возможность анализировать и интерпретировать динамические характеристики сложной нелинейной системы.Представлено структуру та особливості програмного пакета адаптивної тестуючої обробки даних (ATDP Suite). Його застосовано для відтворення динамічних характеристик з експериментальних часових рядів нелінійної та нестабільної електронної системи. Продемонстровано основні методи, реалізовані в ATDP Suite. Застосування ATDP Suite для електромагнітного тестування НВЧ приймачів продемонструвало можливість аналізувати та інтерпретувати динамічні характеристики складної нелінійної системи

    Neutrino mediated muon--electron conversion in nuclei revisited

    Get PDF
    The non-photonic neutrino exchange mechanism of the lepton flavor violating muon-electron conversion in nuclei is revisited. First we determine the nucleon coupling constants for the neutrino exchange mechanism in a relativistic quark model taking into account quark confinement and chiral symmetry requirements. This includes a new, previously overlooked tree-level contribution from neutrino exchange between two quarks in the same nucleon. Then for the case of an additional sterile neutrino we reconsider the coherent mode of this process. The presence of a mixed sterile-active neutrino state heavier than the quark confinement scale Lambda_c (~1 GeV) may significantly improve the prospects for observation of this process in future experiments as compared to the conventional scenario with only light neutrinos. Turning the arguments around we derive new experimental constraints on |U_(mu h)| and |U_(e h)| mixing matrix elements from the non-observation of muon--electron conversion.Comment: 13 pages, RevTex, 1 Postscript figur

    GG-Strands

    Get PDF
    A GG-strand is a map g(t,s):R×RGg(t,{s}):\,\mathbb{R}\times\mathbb{R}\to G for a Lie group GG that follows from Hamilton's principle for a certain class of GG-invariant Lagrangians. The SO(3)-strand is the GG-strand version of the rigid body equation and it may be regarded physically as a continuous spin chain. Here, SO(3)KSO(3)_K-strand dynamics for ellipsoidal rotations is derived as an Euler-Poincar\'e system for a certain class of variations and recast as a Lie-Poisson system for coadjoint flow with the same Hamiltonian structure as for a perfect complex fluid. For a special Hamiltonian, the SO(3)KSO(3)_K-strand is mapped into a completely integrable generalization of the classical chiral model for the SO(3)-strand. Analogous results are obtained for the Sp(2)Sp(2)-strand. The Sp(2)Sp(2)-strand is the GG-strand version of the Sp(2)Sp(2) Bloch-Iserles ordinary differential equation, whose solutions exhibit dynamical sorting. Numerical solutions show nonlinear interactions of coherent wave-like solutions in both cases. Diff(R){\rm Diff}(\mathbb{R})-strand equations on the diffeomorphism group G=Diff(R)G={\rm Diff}(\mathbb{R}) are also introduced and shown to admit solutions with singular support (e.g., peakons).Comment: 35 pages, 5 figures, 3rd version. To appear in J Nonlin Sc

    Abelian Toda field theories on the noncommutative plane

    Full text link
    Generalizations of GL(n) abelian Toda and GL~(n)\widetilde{GL}(n) abelian affine Toda field theories to the noncommutative plane are constructed. Our proposal relies on the noncommutative extension of a zero-curvature condition satisfied by algebra-valued gauge potentials dependent on the fields. This condition can be expressed as noncommutative Leznov-Saveliev equations which make possible to define the noncommutative generalizations as systems of second order differential equations, with an infinite chain of conserved currents. The actions corresponding to these field theories are also provided. The special cases of GL(2) Liouville and GL~(2)\widetilde{GL}(2) sinh/sine-Gordon are explicitly studied. It is also shown that from the noncommutative (anti-)self-dual Yang-Mills equations in four dimensions it is possible to obtain by dimensional reduction the equations of motion of the two-dimensional models constructed. This fact supports the validity of the noncommutative version of the Ward conjecture. The relation of our proposal to previous versions of some specific Toda field theories reported in the literature is presented as well.Comment: v3 30 pages, changes in the text, new sections included and references adde

    Classical/quantum integrability in AdS/CFT

    Full text link
    We discuss the AdS/CFT duality from the perspective of integrable systems and establish a direct relationship between the dimension of single trace local operators composed of two types of scalar fields in N=4 super Yang-Mills and the energy of their dual semiclassical string states in AdS(5) X S(5). The anomalous dimensions can be computed using a set of Bethe equations, which for ``long'' operators reduces to a Riemann-Hilbert problem. We develop a unified approach to the long wavelength Bethe equations, the classical ferromagnet and the classical string solutions in the SU(2) sector and present a general solution, governed by complex curves endowed with meromorphic differentials with integer periods. Using this solution we compute the anomalous dimensions of these long operators up to two loops and demonstrate that they agree with string-theory predictions.Comment: 49 pages, 5 figures, LaTeX; v2: complete proof of the two-loop equivalence between the sigma model and the gauge theory is added. References added; v4,v5,v6: misprints correcte

    Classical/quantum integrability in non-compact sector of AdS/CFT

    Full text link
    We discuss non-compact SL(2,R) sectors in N=4 SYM and in AdS string theory and compare their integrable structures. We formulate and solve the Riemann-Hilbert problem for the finite gap solutions of the classical sigma model and show that at one loop it is identical to the classical limit of Bethe equations of the spin (-1/2) chain for the dilatation operator of SYM.Comment: 27 pages, 1 figure; v2: unphysical windings around the time direction eliminated; v3: dicsussion of finite-size corrections remove
    corecore