345 research outputs found

    Environmental safety monitoring of heavy metals accumulation in some species of Sambucus L.

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    The aim in this work was to monitor heavy metals in plants of elderberry species. The objective of the research was to identify the actual concentrations of heavy metals in the fruits and leaves of the studied elderberry species. The need to determine deviations in the content of heavy metals in various parts of plants arose because the current ecological situation in Belgorod's area requires special attentio

    MULTILAYER STRUCTURES BASED ON PCM WITH TUNABLE REFLECTION AND TRANSMISSION CHARACTERISTICS FOR FULLY OPTICAL ROUTING DEVICES

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    The reported study was funded by RFBR according to the research project # 19-37-60023

    gDsDK(892)g_{D^{\ast}_{s}D K^{\ast}(892)} and gBsBK(892)g_{B^{\ast}_{s}B K^{\ast}(892)} coupling constants in QCD sum rules

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    The coupling constants gDsDK(892)g_{D^{\ast}_{s}D K^{\ast}(892)} and gBsBK(892)g_{B^{\ast}_{s}B K^{\ast}(892)} are calculated in the framework of three-point QCD sum rules. The correlation functions responsible for these coupling constants are evaluated considering contributions of both D(B)D(B) and K(892)K^*(892) mesons as off-shell states, but in the absence of radiative corrections. The results, gDsDK(892)=(4.31±1.42)GeV1g_{D^{\ast}_{s}D K^{\ast}(892)}=(4.31\pm1.42) GeV^{-1} and gBsBK(892)=(3.24±1.08)GeV1g_{B^{\ast}_{s}B K^{\ast}(892)}=(3.24\pm1.08) GeV^{-1} are obtained for the considered strong coupling constants.Comment: 13 Pages and 11 Figure

    Measurement of the analyzing powers in pd elastic and pn quasi-elastic scattering at small angles

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    The analyzing powers in proton-deuteron elastic and proton-neutron quasi-elastic scattering have been measured at small angles using a polarized proton beam at the COSY storage ring incident on an unpolarized deuterium target. The data were taken at 796MeV and five higher energies from 1600MeV to 2400MeV. The analyzing power in pd elastic scattering was studied by detecting the low energy recoil deuteron in telescopes placed symmetrically in the COSY plane to the left and right of the beam whereas for pn quasi-elastic scattering a low energy proton was registered in one of the telescopes in coincidence with a fast scattered proton measured in the ANKE magnetic spectrometer. Though the experiment explores new domains, the results are consistent with the limited published information.Comment: 10 pages with 8 figure

    Toward polarized antiprotons: Machine development for spin-filtering experiments

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    The paper describes the commissioning of the experimental equipment and the machine studies required for the first spin-filtering experiment with protons at a beam kinetic energy of 49.349.3\,MeV in COSY. The implementation of a low-β\beta insertion made it possible to achieve beam lifetimes of τb=8000\tau_{\rm{b}}=8000\,s in the presence of a dense polarized hydrogen storage-cell target of areal density dt=(5.5±0.2)×1013atoms/cm2d_{\rm t}=(5.5\pm 0.2)\times 10^{13}\,\mathrm{atoms/cm^{2}}. The developed techniques can be directly applied to antiproton machines and allow for the determination of the spin-dependent pˉp\bar{p}p cross sections via spin filtering

    First measurements of spin correlations in the np -> d pi^0 reaction

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    The transverse spin correlations Axx and Ayy in the np-> d pi^0 reaction have been measured for the first time in quasi-free kinematics at the COSY-ANKE facility using a polarised deuteron beam incident on a polarised hydrogen cell target. The results obtained for neutron energies close to 353 MeV and 600 MeV are in good agreement with the partial wave analysis of data on the isospin-related pp-> d pi^+ reaction, though the present results cover also the small-angle region, which was largely absent from these data

    Measurement of the Spin-Dependence of the pbar-p Interaction at the AD-Ring

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    We propose to use an internal polarized hydrogen storage cell gas target in the AD ring to determine for the first time the two total spin-dependent pbar-p cross sections sigma_1 and sigma_2 at antiproton beam energies in the range from 50 to 450 MeV. The data obtained are of interest by themselves for the general theory of pbar-p interactions since they will provide a first experimental constraint of the spin-spin dependence of the nucleon-antinucleon potential in the energy range of interest. In addition, measurements of the polarization buildup of stored antiprotons are required to define the optimum parameters of a future, dedicated Antiproton Polarizer Ring (APR), intended to feed a double-polarized asymmetric pbar-p collider with polarized antiprotons. Such a machine has recently been proposed by the PAX collaboration for the new Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt, Germany. The availability of an intense stored beam of polarized antiprotons will provide access to a wealth of single- and double-spin observables, thereby opening a new window on QCD spin physics.Comment: 51 pages, 23 figures, proposal submitted to the SPS committee of CER

    Coherent pion production in proton-deuteron collisions

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    Values of the proton analysing power in the pd3Heπ0/3Hπ+pd\to{}^{3}\textrm{He}\,\pi^0/^{3}\textrm{H}\,\pi^+ reactions at 350-360~MeV per nucleon were obtained by using a polarised proton beam incident on a deuterium cluster-jet target and with a polarised deuteron beam incident on a target cell filled with polarised hydrogen. These results have a much larger angular coverage than existing data. First measurements are also presented of the deuteron vector analysing power and the deuteron-proton spin correlations. Data were also obtained on the deuteron-proton spin correlation and proton analysing power at small angles at 600~MeV per nucleon, though the angular coverage at this energy was much more restricted even when using a deuteron beam. By combining the extrapolated values of the spin correlations to the forward or backward directions with published measurements of the deuteron tensor analysing powers, the relative phases between the two non-vanishing amplitudes were evaluated.Comment: 5 pages, 5 figure

    Measurement of the analysing power in proton-proton elastic scattering at small angles

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    The proton analysing power in pp\vec{p}p elastic scattering has been measured at small angles at COSY-ANKE at 796 MeV and five other beam energies between 1.6 and 2.4 GeV using a polarised proton beam. The asymmetries obtained by detecting the fast proton in the ANKE forward detector or the slow recoil proton in a silicon tracking telescope are completely consistent. Although the analysing power results agree well with the many published data at 796 MeV, and also with the most recent partial wave solution at this energy, the ANKE data at the higher energies lie well above the predictions of this solution at small angles. An updated phase shift analysis that uses the ANKE results together with the World data leads to a much better description of these new measurements.Comment: 5 pages, 3 figure

    Luminescent properties of Bi-doped polycrystalline KAlCl4

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    We observed an intensive near-infrared luminescence in Bi-doped KAlCl4 polycrystalline material. Luminescence dependence on the excitation wavelength and temperature of the sample was studied. Our experimental results allow asserting that the luminescence peaked near 1 um belongs solely to Bi+ ion which isomorphically substitutes potassium in the crystal. It was also demonstrated that Bi+ luminescence features strongly depend on the local ion surroundings
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