24 research outputs found

    Constraints from orbital motions around the Earth of the environmental fifth-force hypothesis for the OPERA superluminal neutrino phenomenology

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    It has been recently suggested by Dvali and Vikman that the superluminal neutrino phenomenology of the OPERA experiment may be due to an environmental feature of the Earth, naturally yielding a long-range fifth force of gravitational origin whose coupling with the neutrino is set by the scale M_*, in units of reduced Planck mass. Its characteristic length lambda should not be smaller than one Earth's radius R_e, while its upper bound is expected to be slightly smaller than the Earth-Moon distance (60 R_e). We analytically work out some orbital effects of a Yukawa-type fifth force for a test particle moving in the modified field of a central body. Our results are quite general since they are not restricted to any particular size of lambda; moreover, they are valid for an arbitrary orbital configuration of the particle, i.e. for any value of its eccentricity ee. We find that the dimensionless strength coupling parameter alpha is constrained to |alpha| <= 1 10^-10-4 10^-9 for 1 R_e <= lambda <= 10 R_e by the laser data of the Earth's artificial satellite LAGEOS II, corresponding to M_* >= 4 10^9 -1.6 10^10. The Moon perigee allows to obtain |alpha| <= 3 10^-11 for the Earth-Moon pair in the range 15 R_e <= lambda = 3 10^10 - 4.5 10^10. Our results are neither necessarily limited to the superluminal OPERA scenario nor to the Dvali-Vikman model, in which it is M_* = 10^-6 at lambda = 1 R_e, in contrast with our bounds: they generally extend to any theoretical scenario implying a fifth-force of Yukawa-type.Comment: LaTex2e, 18 pages, 4 figures, 1 table, 81 reference

    Possible variations of the fine structure constant α\alpha and their metrological significance

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    We briefly review the recent experimental results on possible variations of the fine structure constant α\alpha on the cosmological time scale and its position dependence. We outline the theoretical grounds for the assumption that α\alpha might be variable, mention some phenomenological models incorporating a variable α\alpha into the context of modern cosmology and discuss the significance of possible α\alpha variations for theoretical and practical metrology.Comment: Latex, 17 pages, brief review. References updated, minor errors remove

    Theoretical Investigation of the Structure and Physicochemical Properties of Alkaline and Alkaline Earth Metal Perchlorate Solutions in Sulfolane

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    To assess the possibility of using solutions of perchlorates of alkali and alkaline earth metals in sulfolane as electrolytes for electrochemical energy storage devices with metal negative electrodes, the physicochemical properties of 0.5 M solutions of Me(ClO4)n (Me = Li, Na, K, Mg, and Ca) in sulfolane were simulated by the method of molecular dynamics. The density, viscosity, conductivity, self-diffusion coefficients, and transport numbers are calculated. Satisfactory agreement between the calculated and experimentally measured properties of 0.5 M solutions of LiClO4 and NaClO4 in sulfolane suggests that the calculated values of the physicochemical properties of solutions of K, Mg, and Ca perchlorates are also close to real values. The study of the structure of solvate complexes of salts of alkali and alkaline earth metals with sulfolane by quantum chemical and molecular dynamics modeling showed that the first solvate shell of metal cations consists of sulfolane molecules. Regardless of the nature of the cation, sulfolane is coordinated to the metal cation by only one oxygen atom. Based on the analysis of the calculated values of the physicochemical properties of solutions of metal perchlorates in sulfolane, it can be concluded that they can be used as electrolyte systems of electrochemical energy storage devices with negative electrodes made of alkali and alkaline earth metals

    LUMINESCENCE OF ALUMINUM OXIDE FILMS AND PERSPECTIVES OF THEIR APPLICATION IN NANOPHOTONICS PLANAR MICROSTRUCTURES

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    Various methods of fabrication the luminescent film structures based on porous anodic alumina are analyzed. Manufacturing of luminescent structures by anodizing aluminum in oxalic acid allows observation of visible to the naked eye photoluminescence in the blue range, which remains under ambient conditions for a year or longer. Alumina xerogel prepared in a form of powder demonstrates luminescence in the blue range, which disappears totally after annealing at 800 ÂşC. Photoluminescence of porous anodic alumina which contains terbium ions in the xerogel of alumina or deposited from solutions of salts formed in the anodic alumina pores has been investigated. The perspectives of formation of planar microstructures using a porous anodic alumina supporting electromagnetic whispering gallery modes are discussed
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