622 research outputs found

    Towards a Maximal Mass Model

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    We investigate the possibility to construct a generalization of the Standard Model, which we call the Maximal Mass Model because it contains a limiting mass MM for its fundamental constituents. The parameter MM is considered as a new universal physical constant of Nature and therefore is called the fundamental mass. It is introduced in a purely geometrical way, like the velocity of light as a maximal velocity in the special relativity. If one chooses the Euclidean formulation of quantum field theory, the adequate realization of the limiting mass hypothesis is reduced to the choice of the de Sitter geometry as the geometry of the 4-momentum space. All fields, defined in de Sitter p-space in configurational space obey five dimensional Klein-Gordon type equation with fundamental mass MM as a mass parameter. The role of dynamical field variables is played by the Cauchy initial conditions given at x5=0x_5 = 0, guarantying the locality and gauge invariance principles. The corresponding to the geometrical requirements formulation of the theory of scalar, vector and spinor fields is considered in some detail. On a simple example it is demonstrated that the spontaneously symmetry breaking mechanism leads to renormalization of the fundamental mass MM. A new geometrical concept of the chirality of the fermion fields is introduced. It would be responsible for new measurable effects at high energies EME \geq M. Interaction terms of a new type, due to the existence of the Higgs boson are revealed. The most intriguing prediction of the new approach is the possible existence of exotic fermions with no analogues in the SM, which may be candidate for dark matter constituents.Comment: 28 page

    Novel superconducting phases of Tl-based compounds

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    Researchers report the measurements of the I(sub c)(T) of the 102 K phase. They also discuss briefly the composition of the lattice parameters and the ac susceptibility relation to the grain size and microstructure

    Novel superconducting phases of Tl-based compounds

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    Several new superconducting phases of the Tl-based compounds were prepared. Structural studies revealed cell lengths of 31.9 A and longer. Properties of Ce-containing compounds are also discussed

    Gait Measurements and Motor Recovery after Stroke

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    2000 Mathematics Subject Classification: 62P10, 92C20Gait analysis is one of the methods used for estimation of the degree of restoration of motor recovery after stroke. The purpose of the present study was to examine the diagnostic value of the footprint parameters and their relationship with the functional ambulation profile (FAP) scores provided automatically by the pressure sensor walkway system for gait examination. The patterns of walking were studied in a group of 23 patients with chronic unilateral stroke and 72 healthy subjects. Among the measured gait variables the peak times of the footprints were found as most informative parameters. Their predictive value was compared with some other gait indicators for motor recovery after stroke

    Towards a Geometric Approach to the Formulation of the Standard Model

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    A geometric interpretation of the spontaneous symmetry breaking effect, which plays a key role in the Standard Model, is developed. The advocated approach is related to the effective use of the momentum 4-spaces of the constant curvature, de Sitter and anti de Sitter, in the apparatus of quantum field theory.Comment: 8 pages, LaTe

    Estimation of errors in text and data processing

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    The company Adiss Lab Lts. obtained 1 000 000 medical reports that are either in free form text, or in XML format. One of the main goals of their development is to integrate an algorithm for information extraction (IE) in their platform. The verification of the algorithm’s output for a report is done by a medical doctor (MD) for a certain fee. Validating the correctness of all data would be overwhelming and very expensive. Hence, the problem, as presented by the company, is to provide a method (algorithm) which determines the minimum amount of reports that will validate the correctness of the IE algorithm and a procedure for selecting these reports. In order to solve the problem we have considered an algorithm-centric approach uses active learning and semi-supervised learning

    Recoilless resonant neutrino capture and basics of neutrino oscillations

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    It is shown that the experiment on recoilless resonant emission and absorption of νˉe\bar \nu_{e}, proposed recently by Raghavan, could have an important impact on our understanding of the physics of neutrino oscillations.Comment: Additional information in the last chapte

    Antideuteron and deuteron production in mid-central Pb+Pb collisions at 158AA GeV

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    Production of deuterons and antideuterons was studied by the NA49 experiment in the 23.5% most central Pb+Pb collisions at the top SPS energy of sNN\sqrt{s_{NN}}=17.3 GeV. Invariant yields for dˉ\bar{d} and dd were measured as a function of centrality in the center-of-mass rapidity range 1.2<y<0.6-1.2<y<-0.6. Results for dˉ(d)\bar{d}(d) together with previously published pˉ(p)\bar{p}(p) measurements are discussed in the context of the coalescence model. The coalescence parameters B2B_2 were deduced as a function of transverse momentum ptp_t and collision centrality.Comment: 9 figure
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