3,147 research outputs found

    Possibility of the new type phase transition

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    The scalar field theory and the scalar electrodynamics quantized in the flat gap are considered. The dynamical effects arising due to the boundary presence with two types of boundary conditions (BC) satisfied by scalar fields are studied. It is shown that while the Neumann BC lead to the usual scalar field mass generation, the Dirichlet BC give rise to the dynamical mechanism of spontaneous symmetry breaking. Due to the later, there arises the possibility of the new type phase transition from the normal to spontaneously broken phase. The decreasing in the characteristic size of the quantization region (the gap size here) and increasing in the temperature compete with each other, tending to transport the system in the spontaneously broken and in the normal phase, respectively. The system evolves with a combined parameter, simultaneously reflecting the change in temperature and in the size. As a result, at the critical value of this parameter there occurs the phase transition from the normal phase to the spontaneously broken one. In particular, the usual massless scalar electrodynamics transforms to the Higgs model

    The Triple Higgs Boson Self-Coupling at Future Linear e+e- Colliders Energies: ILC and CLIC

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    We analyzed the triple Higgs boson self-coupling at future e+ee^{+}e^{-} colliders energies, with the reactions e+ebbˉHH,ttˉHHe^{+}e^{-}\to b \bar b HH, t \bar t HH. We evaluate the total cross-sections for both bbˉHHb\bar bHH and ttˉHHt\bar tHH, and calculate the total number of events considering the complete set of Feynman diagrams at tree-level. We vary the triple coupling κλ3H\kappa\lambda_{3H} within the range κ=1\kappa=-1 and +2. The numerical computation is done for the energies expected to be available at a possible Future Linear e+ee^{+}e^{-} Collider with a center-of-mass energy 800,1000,1500800, 1000, 1500 GeVGeV and a luminosity 1000 fb1fb^{-1}. Our analysis is also extended to a center-of-mass energy 3 TeVTeV and luminosities of 1000 fb1fb^{-1} and 5000 fb1fb^{-1}. We found that for the process e+ebbˉHHe^{+}e^{-}\to b \bar b HH, the complete calculation differs only by 3% from the approximate calculation e+eZHH(Zbbˉ)e^{+}e^{-}\to ZHH(Z\to b\bar b), while for the process e+ettˉHHe^{+}e^{-}\to t \bar tHH, the expected number of events, considering the decay products of both tt and HH, is not enough to obtain an accurate determination of the triple Higgs boson self-coupling.Comment: 19 pages, 12 figure

    Application of remote sensing to state and regional problems

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    There are no author-identified significant results in this report

    The mouse alpha-globin cluster: A paradigm for studying genome regulation and organization

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    The mammalian globin gene clusters provide a paradigm for studying the relationship between genome structure and function. As blood stem cells undergo lineage specification and differentiation to form red blood cells, the chromatin structure and expression of the α-globin cluster change. The gradual activation of the α-globin genes in well-defined cell populations has enabled investigation of the structural and functional roles of its enhancers, promoters and boundary elements. Recent studies of gene regulatory processes involving these elements at the mouse α-globin cluster have brought new insights into the general principles underlying the three-dimensional structure of the genome and its relationship to gene expression throughout time

    Does Magnetic Charge Imply a Massive Photon ?

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    In Abelian theories of monopoles the magnetic charge is required to be enormous. Using the electric-magnetic duality of electromagnetism it is argued that the existence of such a large, non-perturbative magnetic coupling should lead to a phase transition where magnetic charge is permanently confined and the photon becomes massive. The apparent masslessness of the photon could then be used as an argument against the existence of such a large, non-perturbative magnetic charge. Finally it is shown that even in the presence of this dynamical mass generation the Cabbibo-Ferrari formulation of magnetic charge gives a consistent theory.Comment: 10 pages LaTe

    Application of remote sensing to state and regional problems

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    The author has identified the following significant results. The Lowndes County data base is essentially complete with 18 primary variables and 16 proximity variables encoded into the geo-information system. The single purpose, decision tree classifier is now operational. Signatures for the thematic extraction of strip mines from LANDSAT Digital data were obtained by employing both supervised and nonsupervised procedures. Dry, blowing sand areas of beach were also identified from the LANDSAT data. The primary procedure was the analysis of analog data on the I2S signal slicer

    Observation of Leggett's collective mode in a multi-band MgB2 superconductor

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    We report observation of Leggett's collective mode in a multi-band MgB2 superconductor with T_c=39K arising from the fluctuations in the relative phase between two superconducting condensates. The novel mode is observed by Raman spectroscopy at 9.4 meV in the fully symmetric scattering channel. The observed mode frequency is consistent with theoretical considerations based on the first principle computations.Comment: Accepted for PR

    Probing the Higgs mechanism via γγW+W\gamma\gamma\to W^+W^-

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    We investigate the sensitivity of the reaction γγW+W\gamma\gamma\to W^+W^- to the Higgs sector based on the complete one-loop corrections in the minimal Standard Model and the gauged non-linear σ\sigma-model. While this sensitivity is very strong for the suppressed cross-section of equally polarized photons and longitudinal W bosons, it is only marginal for the dominant mode of transverse polarizations. The corrections within the σ\sigma-model turn out to be UV-finite in accordance with the absence of \log\MH terms in the Standard Model with a heavy Higgs boson.Comment: 12 pages uuencoded postscrip

    Development of form and function in peripheral auditory structures of the zebrafish (Danio rerio)

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    Investigations of the development of auditory form and function have, with a few exceptions, thus far been largely restricted to birds and mammals, making it difficult to postulate evolutionary hypotheses. Teleost fishes represent useful models for developmental investigations of the auditory system due to their often extensive period of posthatching development and the diversity of auditory specializations in this group. Using the auditory brainstem response and morphological techniques we investigated the development of auditory form and function in zebrafish (Danio rerio) ranging in size from 10 to 45 mm total length. We found no difference in auditory sensitivity, response latency, or response amplitude with development, but we did find an expansion of maximum detectable frequency from 200 Hz at 10 mm to 4000 Hz at 45 mm TL. The expansion of frequency range coincided with the development of Weberian ossicles in zebrafish, suggesting that changes in hearing ability in this species are driven more by development of auxiliary specializations than by the ear itself. We propose a model for the development of zebrafish hearing wherein the Weberian ossicles gradually increase the range of frequencies available to the inner ear, much as middle ear development increases frequency range in mammals
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