789 research outputs found

    Whispering Gallery States of Antihydrogen

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    We study theoretically interference of the long-living quasistationary quantum states of antihydrogen atoms, localized near a concave material surface. Such states are an antimatter analog of the whispering gallery states of neutrons and matter atoms, and similar to the whispering gallery modes of sound and electro-magnetic waves. Quantum states of antihydrogen are formed by the combined effect of quantum reflection from van der Waals/Casimir-Polder (vdW/CP) potential of the surface and the centrifugal potential. We point out a method for precision studies of quantum reflection of antiatoms from vdW/CP potential; this method uses interference of the whispering gallery states of antihydrogen.Comment: 13 pages 7 figure

    Antiproton-Hydrogen annihilation at sub-kelvin temperatures

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    The main properties of the interaction of ultra low-energy antiprotons (E106% E\le10^{-6} a.u.) with atomic hydrogen are established. They include the elastic and inelastic cross sections and Protonium (Pn) formation spectrum. The inverse Auger process (Pn+eH+pˉPn+e \to H+\bar{p}) is taken into account in the framework of an unitary coupled-channels model. The annihilation cross-section is found to be several times smaller than the predictions made by the black sphere absorption models. A family of pˉH\bar{p}H nearthreshold metastable states is predicited. The dependence of Protonium formation probability on the position of such nearthreshold S-matrix singularities is analysed. An estimation for the HHˉH\bar{H} annihilation cross section is obtained.Comment: latex.tar.gz file, 22 pages, 9 figure

    Morphological and structural features of the CdxPb1−xS films obtained by CBD from ethylenediamine-citrate bath

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    The calculating of ionic equilibria in the system «Pb(CH3COO)2 - CdCl2 - Na3C6H5O7 - ‎(NH3)2(CH2)2 - N2H4CS» allowed us to find conditions and concentration regions of PbS and CdS co-deposition. The determined conditions provided the CBD obtaining of CdxPb1−xS (0 ≤ x ≤ 0.033) substitutional solid solutions films with a cubic structure B1 (space group Fm ) with the grains preferred orientation (200). We established the evolution of the surface morphology of the synthesized films from cubic crystallites to hierarchical structure of globular aggregates by scanning electron microscopy. A quantitative analysis of diffraction patterns showed a decrease of microstrains in CdxPb1−xS films by a about factor of 3 with an increase of the cadmium chloride concentration in the reaction mixture from 0.005 to 0.14 mol/l. The excess of the cadmium content, established by EDX analysis, in the studied films as compared to its content in the solid solution is associated with the additional formation of the amorphous CdS phase up to 72 mol %.A Corrigendum is available for this article at https://doi.org/10.15826/chimtech.2021.8.2.12

    Neutron diffraction constraint on spin-dependent short range interaction

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    The direct constraint on the parameters of short range pseudomagnetic interaction of free neutron with matter is obtained from the recent test experiment on a search for neutron EDM by crystal-diffraction method. It is shown that this constraint on a product of scalar to pseudo-scalar coupling constants gsgpg_s g_p is better than that of any other method for the range λ<105\lambda < 10^{-5}cm

    Technical and tactical training of kickboxers and the results of performances at international tournaments in tatami

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    The popularization of various kickboxing disciplines in Russia has made it possible to obtain high results in this sport. However, high rates are absent in the least traumatic types tactical training of athletes - point fights and kick-lights, the fights of which take place on the tatami.For tatami disciplines are characterized by individual actions or their combinations, performed in the framework of attacks and counterattacks. The quality of an athlete's technical and tactical readiness is reflected in the overall performance of the athlete. In this regard, it is necessary to pay attention to the technical and tactical training of athletes-kickboxers for international competition

    Low-energy Antiproton Interaction with Helium

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    An ab initio potential for the interaction of the neutral helium atom with antiprotons and protons is calculated using the Born-Oppenheimer approximation. Using this potential, the annihilation cross section for antiprotons in the energy range 0.01 microvolt to 1 eV is calculated.Comment: 13 pages, 7 figures, LaTe
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