4,523 research outputs found

    Collective and fractal properties of pion jets in the four-velocity space at intermediate energies

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    Experimental results are presented for study of collective and fractal properties of soft pion jets in the space of relative four-dimensional velocities. Significant decreasing is obtained for mean square of second particle distances from jet axis for pion-proton interactions at initial energies ∼3\sim 3 GeV in comparison with hadron-nuclear collisions at close energies. The decreasing results in power dependence of distance variable on collision energy for range ∼2βˆ’4\sim 2 - 4 GeV. The observation allows us to estimate the low boundary of manifestation of color degree of freedom in pion jet production. Cluster dimension values were deduced for pion jets in various reactions. Fractional values of this dimension indicate on the manifestation of fractal-like properties by pion jets. Changing of mean kinetic energy of jet particles and fractal dimension with initial energy increasing is consistent with suggestion for presence of color degrees of freedom in pion jet production at intermediate energies.Comment: The conference "Physics of fundamental interactions". ITEP, Moscow, Russia. November 23 - 27, 200

    Probing the deuteron structure at small N-N distances by cumulative pion production

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    The fragmentation of deuterons into pions emitted forward in the kinematic region forbidden for free nucleon-nucleon collisions is analyzed. It is shown that the inclusion of the non-nucleonic degrees of freedom in a deuteron results in a satisfactory description of the data for the inclusive pion spectrum and improves the description of the data about T20T_{20}. According to the data, T20T_{20} has very small positive values, less than 0.2, which contradicts the theoretical calculations ignoring these degrees of freedom.Comment: 3 pages, 2 postscript figures; to appear in the proceedings of Conference on Quarks and Nuclear Physics (QNP 2002), Julich, Germany, 9-14 Jun 200

    On QCD Q2Q^2-evolution of Deuteron Structure Function F2D(xD,Q2)F_2^D(x_D,Q^2) for xD>1x_D>1

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    The deep-inelastic deuteron structure function (SF) F2D(xD,Q2)F_2^D(x_D,Q^2) in the covariant approach in light-cone variables is considered. The xDx_D and Q2Q^2-dependences of SF are calculated. The QCD analysis of generated data both for non-cumulative xD1x_D1 ranges was performed. It was shown that Q2Q^2-evolution of SF is valid for ranges 0.275<xD<0.850.275<x_D<0.85 and 1.1<xD<1.41.1<x_D<1.4 for the same value of QCD scale parameter Ξ›{\Lambda}. It was found the xDx_D-dependence of SF for the ranges is essentially different.Comment: LaTeX, 10 pages, 2 Postscript figure

    Using mosaic crystals for the generation of intense X-ray beams

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    The parametric X-ray (PXR) yield due to 500-MeV electrons in a 2-mm-thick diamond crystal with a mosaicity angle of ~0.2 mrad has been studied. It is shown that the mosaic crystal structure leads to a significant (about fourfold) increase in the PXR yield doe to the contribution of diffracted bremsstrahlung radiationye

    Enabling comparison of UrQMD with Geant4 hadronic models

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    Geant4 has an abundant set of physics models that handle the diverse interaction of particles with matter across a wide energy range. However, there are also many well established reaction codes currently used in the same fields where Geant4 is applied. One such code is the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model. In order to take advantage of the UrQMD code, we create a tool to enable comparisons among UrQMD and Geant4 hadronic models. This tool allows a user to process the output file of UrQMD through Geant4 toolkit, while at the same time, can choose among different Geant4 hadronic model generators. As an example, the UrQMD model is compared with the HARP-CDP experimental data and with the Binary and FRITIOF generators, in the framework of Geant4. It is shown that the UrQMD model can better reproduce charged pion production for p+Cu and Pb interactions at 3, 8 and 15 GeV/c, and is a good candidate for Geant4 hadronic models.Comment: 17 pages, 5 Figure

    Simulation and optimization of occupant behavior in energy consumption

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    One of the biggest part of building energy consumption is influenced by human element. Each occupant interacts with systems of his house, work place, etc. in his own way. This paper introduced the potential of following working with optimization of human element and showed possible solutions of reduction negative impact of occupant behavior on energy usage taking into account mental, economical and technologic aspects.Одной ΠΈΠ· основных статСй Π² энСргопотрСблСнии Π·Π΄Π°Π½ΠΈΠΉ являСтся чСловСчСский Ρ„Π°ΠΊΡ‚ΠΎΡ€. ΠšΠ°ΠΆΠ΄Ρ‹ΠΉ ΠΏΠΎΡ‚Ρ€Π΅Π±ΠΈΡ‚Π΅Π»ΡŒ элСктроэнСргии ΠΏΠΎ-своСму взаимодСйствуСт с систСмами Π΄ΠΎΠΌΠ° ΠΈ Ρ€Π°Π±ΠΎΡ‡Π΅Π³ΠΎ мСста. Π’ Π΄Π°Π½Π½ΠΎΠΌ Π΄ΠΎΠΊΠ»Π°Π΄Π΅ описан ΠΏΠΎΡ‚Π΅Π½Ρ†ΠΈΠ°Π» Π΄Π°Π»ΡŒΠ½Π΅ΠΉΡˆΠΈΡ… Ρ€Π°Π±ΠΎΡ‚ ΠΏΠΎ ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ чСловСчСского Ρ„Π°ΠΊΡ‚ΠΎΡ€Π°, ΠΏΠΎΠΊΠ°Π·Π°Π½Ρ‹ Π²ΠΎΠ·ΠΌΠΎΠΆΠ½Ρ‹Π΅ ΠΌΠΎΠ΄Π΅Π»ΠΈ ΠΏΠΎ сниТСнию Π½Π΅Π³Π°Ρ‚ΠΈΠ²Π½ΠΎΠ³ΠΎ воздСйствия ΠΆΠΈΠ»ΡŒΡ†Π° Π½Π° энСргозатраты, с ΡƒΡ‡Ρ‘Ρ‚ΠΎΠΌ ΠΌΠ΅Π½Ρ‚Π°Π»ΡŒΠ½Ρ‹Ρ… особСнностСй, экономичСского, психологичСского ΠΈ тСхнологичСского аспСктов

    Experimental observation of parametric X-ray radiation directed along the propagation velocity of relativistic electrons in a tungsten crystal

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    Parametric X-ray radiation (PXR) due to dynamic diffraction of relativistic electrons is experimentally observed at small angles to the propagation velocity of electrons in a tungsten crystal. The specific features of the experimental method are described, and forward PXR reflections from two crystallographic planes of tungsten are reliably measuredyesBelgorod State Universit
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