911 research outputs found

    R-parity violating supersymmetric contributions to the P, CP-odd electron-nucleon interaction at the one-loop level

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    The contribution of the R-parity violating minimal supersymmetric Standard model (RPVMSSM) at the one-loop level to the 199Hg atomic electric dipole moment (EDM) through P, CP-odd electron-nucleon (e-N) interaction is calculated. We show that the current experimental data of the 199Hg EDM give tighter constraints on some of the imaginary parts of R-parity violating (RPV) coupling than those currently known. We add also the analysis of the P, CP-odd 4-quark interaction generated by R-parity violating interactions at the one-loop level, and discuss the possibility to constrain them in future experiments.Comment: 9 pages, 3 figure

    Current Trends in Global Supply Chain Management Investment Policy

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    Abstract- To achieve the Sustainable Development Goals of the world economy, significant financial resources and global supply chain are needed. Priority issues are related to the use of investment resources. Almost all sectors of the economy have a real need for investment. Domestic investments is not enough for countries to implement effective structural policies and upgrade fixed assets. They are forced to attract foreign investment. The annual requirements for international investment reach several trillion US dollars. However, foreign investors are in no hurry to expand investments in the economy of foreign countries. Moreover, in 2017-2019 there is a decrease in global direct foreign investment flows. This is largely due to a noticeable reduction in US investment in the economies of the European Union and China as a result of the tightening of the American protectionism policy pursued by the D. Trump administration and the US Federal Reserve to strengthen regulation of foreign companies in the US market. A decrease in the level of international investment under the worsening business climate in the world leads to the increased competition between countries for attracting foreign investment

    Atomic electric dipole moments of He and Yb induced by nuclear Schiff moments

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    We have calculated the atomic electric dipole moments (EDMs) d of ^3He and ^{171}Yb induced by their respective nuclear Schiff moments S. Our results are d(He)= 8.3x10^{-5} and d(Yb)= -1.9 in units 10^{-17}S/(e{fm}^3)e cm. By considering the nuclear Schiff moments induced by the parity and time-reversal violating nucleon-nucleon interaction we find d(^{171}Yb)~0.6d(^{199}Hg). For ^3He the nuclear EDM coupled with the hyperfine interaction gives a larger atomic EDM than the Schiff moment. The result for ^3He is required for a neutron EDM experiment that is under development, where ^3He is used as a comagnetometer. We find that the EDM for He is orders of magnitude smaller than the neutron EDM. The result for Yb is needed for the planning and interpretation of experiments that have been proposed to measure the EDM of this atom.Comment: 4 page

    Gradients of Taxonomic Diversity among Local Floras in the Russian Arctic

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    Latitudinal and longitudinal changes in taxonomic variables were analyzed in 319 local floras in the Russian Arctic. Within the studied segment of latitudinal gradient, most changes can be described in terms of linear regression with negative coefficients (a number of species, genera and families), or positive coefficients (a proportion of the leading families and genera). However, the mean number of species in a family or genus almost does not change with increasing latitude, although it slightly increases as one moves eastward. The proportion of monocots does not correlate with latitude, but slightly decreases as one moves eastward. Proportions of various families change asynchronously. Although correlation with longitude was less pronounced, mean species richness was specific to many subprovinces, even within a certain subzone. These differences reflect both the diversity of landscapes and the history of flora formation. Keywords: the Arctic, local floras, latitudinal and longitudinal gradient, floristic subprovince

    Stromal and Tumor Glioma-Derived Cells with Similar Characteristics have Differences in α-Smooth Muscle Actin Expression and Localization

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    Gliomas are solid brain tumors composed of tumor cells and recruited heterogenic stromal components. The study of the interactions between the perivascular niche and its surrounding cells is of great value in unraveling mechanisms of drug resistance in malignant gliomas. In this study, we isolated the stromal diploid cell population from oligodendroglioma and a mixed population of tumor aneuploid and stromal diploid cells from astrocytoma specimens. The stromal cells expressed neural stem/progenitor and mesenchymal markers showing the same discordant phenotype that is typical for glioma cells. Moreover, some of the stromal cells expressed CD133. For the first time, we demonstrated that this type of stromal cells had the typical myofibroblastic phenotype as the α-SMA+ cells formed α-SMA fibers and exhibited the specific function to deposit extracellular matrix (ECM) proteins at least in vitro. Immunofluorescent analysis showed diffuse or focal α-SMA staining in the cytoplasm of the astrocytoma-derived, A172, T98G, and U251MG glioma cells. We could suggest that α-SMA may be one of the main molecules, bearing protective functions. Possible mechanisms and consequences of α-SMA disruptions in gliomas are discussed

    Experimental investigation of high-energy photon splitting in atomic fields

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    The new data analysis of the experiment, where the photon splitting in the atomic fields has been observed for the first time, is presented. This experiment was performed at the tagged photon beam of the ROKK-1M facility at the VEPP-4M collider. In the energy region of 120-450 MeV, the statistics of 1.61091.6\cdot 10^9 photons incident on the BGO target was collected. About 400 candidates to the photon splitting events were reconstructed. Within the attained experimental accuracy, the experimental results are consistent with the cross section calculated exactly in an atomic field. The predictions obtained in the Born approximation significantly differ from the experimental results.Comment: 11 pages, 6 figures, LaTe

    Slightly Non-Minimal Dark Matter in PAMELA and ATIC

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    We present a simple model in which dark matter couples to the standard model through a light scalar intermediary that is itself unstable. We find this model has several notable features, and allows a natural explanation for a surplus of positrons, but no surplus of anti-protons, as has been suggested by early data from PAMELA and ATIC. Moreover, this model yields a very small nucleon coupling, well below the direct detection limits. In this paper we explore the effect of this model in both the early universe and in the galaxy.Comment: 7 pages, 6 figures, v3: updated for new data, added discussion of Ferm

    Measurement of J/ψγηcJ/\psi\to\gamma\eta_{\rm c} decay rate and ηc\eta_{\rm c} parameters at KEDR

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    Using the inclusive photon spectrum based on a data sample collected at the J/ψJ/\psi peak with the KEDR detector at the VEPP-4M e+ee^+e^- collider, we measured the rate of the radiative decay J/ψγηcJ/\psi\to\gamma\eta_{\rm c} as well as ηc\eta_{\rm c} mass and width. Taking into account an asymmetric photon lineshape we obtained Γγηc0=2.98±0.180.33+0.15\Gamma^0_{\gamma\eta_{\rm c}}=2.98\pm0.18 \phantom{|}^{+0.15}_{-0.33} keV, Mηc=2983.5±1.43.6+1.6M_{\eta_{\rm c}} = 2983.5 \pm 1.4 \phantom{|}^{+1.6}_{-3.6} MeV/c2c^2, Γηc=27.2±3.12.6+5.4\Gamma_{\eta_{\rm c}} = 27.2 \pm 3.1 \phantom{|}^{+5.4}_{-2.6} MeV.Comment: 6 pages, 3 figure
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