12,096 research outputs found

    Analytical representation of elastic scattering cross sections of low energy electrons by atmospheric gases

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    Analytical representations of the elastic scattering cross sections of electrons with energies of 0.01-1 keV in atmospheric gases of N2, O2, O are given. These representations are suitable for the Monte Carlo method

    Visualization of the 3-dimensional flow around a model with the aid of a laser knife

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    A method for visualizing the three-dimensional flow around models of various shapes in a wind tunnel at a Mach number of 5 is described. A laser provides a planar light flux such that any plane through the model can be selectively illuminated. The shape of shock waves and separation regions is then determined by the intensity of light scattered by soot particles in the flow

    Soyuz 22: New contribution to earth study from space

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    The mission of space flight Soyuz-22 was to develop new and improved methods and means for finding tthe Earth's natural resources from outer space to aid the economy. With the help of the new multispectral space camera, MKF-6, the cosmonauts were able to photograph selected areas of U.S.S.R. and the German Democratic Republic in 4 visible and 2 infrared regions of the spectrum. The MKF-6 can simultaneously photograph areas in 6 spectral regions and register both the natural electromagnetic radiation of surface objects and the solar radiation reflected by them

    Quark model description of the tetraquark state X(3872) in a relativistic constituent quark model with infrared confinement

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    We explore the consequences of treating the X(3872) meson as a tetraquark bound state. As dynamical framework we employ a relativistic constituent quark model which includes infrared confinement in an effective way. We calculate the decay widths of the observed channels X-> Jpsi+2\pi (3\pi) and X-> \bar D0+D0+\pi0 via the intermediate off--shell states X-> Jpsi+\rho(\omega) and X-> \bar D + D*. For reasonable values of the size parameter of the X(3872) we find consistency with the available experimental data. We also discuss the possible impact of the X(3872) in a s-channel dominance description of the Jpsi-dissociation cross section.Comment: 9 pages, 5 figures; discussion and references added, accepted in Phys. Rev.
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