591 research outputs found

    Production of a0a_0-mesons in the reactions πNa0N\pi N \to a_0 N and ppda0+p p \to d a_0^+ at GeV energies

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    We investigate the reactions πNa0N\pi N \to a_0 N and ppda0+p p \to d a_0^+ near threshold and at medium energies. An effective Lagragian approach and the Regge pole model are applied to analyze different contributions to the cross section of the reaction πNa0N\pi N \to a_0 N. These results are used to calculate the differential and total cross sections of the reaction ppda0+p p \to d a_0^+ within the framework of the two-step model in which two nucleons produce an a0a_0-meson via π\pi -meson exchange and fuse to a deuteron. The necessity of new measurements on a0a_0 production and branching fractions (of its decay to the KKˉK\bar K and πη\pi\eta channels) is emphasized for clarifying the a0a_0 structure. Detailed predictions for the reaction ppda0+pp \to d a_0^+ are presented for the energy regime of the proton synchrotron COSY-J\"ulich.Comment: 9 pages, including 6 eps figure

    Polarization observables in high-energy deuteron photodisintegration within the Quark-Gluon Strings Model

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    Deuteron two-body photodisintegration is analysed within the framework of the Quark-Gluon Strings Model. The model describes fairly well the recent experimental data from TJNAF in the few GeV region. Angular distributions at different γ\gamma-energies are presented and the effect of a forward-backward asymmetry is discussed. New results from the QGSM for polarization observables from 1.5 -- 6 GeV are presented and compared with the available data.Comment: 3 pages, LaTeX, 4 postscript figures; contribution to QNP2002, Juelich, June 10-14, 200

    Deuteron photodisintegration within the Quark-Gluon Strings Model and QCD motivated nonlinear Regge trajectories

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    We investigate deuteron two-body photodisintegration within the framework of the Quark-Gluon Strings Model with nonlinear baryon Regge trajectories. Special attention is paid to the use of QCD motivated Regge trajectories of the logarithmic and square-root form which have been suggested recently by Brisudov\'{a}, Burakovsky and Goldman. We find that the recent experimental data from TJNAF in the few GeV region can reasonably be described by the model. Angular distributions at different γ\gamma-energies are presented and the effect of a forward-backward asymmetry is discussed. Predictions for the energy dependence of dσ/dtd\sigma/dt at higher energies and different Θcm\Theta_{cm} are presented, too.Comment: 21 pages, LaTeX, including 6 postscript figures; submitted to Phys. Rev.

    The Role of Non-Profit Organizations in Improving the Efficiency of Managing Corporate Social Responsibility Programs of Russian Enterprises

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    The purpose of the presented study should be considered the identification of promising areas and the organizational and economic mechanism for the potential participation of non-profit organizations in the implementation of projects and programs of corporate social responsibility based on the use of public-private partnership opportunities in solving systemic problems of regional development, primarily in such urgent areas of social development as social sphere and reduction of differentiation between population groups. The article presents methodological approaches that reflect the topical issues of determining the place and role of NGOs in the Russian economy. In modern conditions, non-profit organizations should become an important participant in the comprehensive implementation of corporate social responsibility programs for various business entities within the same territory and region, which will increase the effectiveness of financial investments of all market participants, including the state through the use of the mechanism of public-private partnership, and to create a transparent system of accounting and control of the results of this activity in relation to the obtained socio-economic effects

    Behaviour of the Blazar CTA 102 during two giant outbursts

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    Blazar CTA 102 underwent exceptional optical and high-energy outbursts in 2012 and 2016-2017. We analyze its behaviour during these events, focusing on polarimetry as a tool that allows us to trace changes in the physical conditions and geometric configuration of the emission source close to the central black hole. We also use Fermi gamma-ray data in conjunction with optical photometry in an effort to localize the origin of the outbursts.AST-1615796 - Boston Universit

    Innovations in warehouse logistics as factor of development of automation professions

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    The article analyzes the scientific achievements in the field of transprofessionalism, as well as examples of innovations in the field of warehouse logistics, which lead to an increase in the level of diversification of labor, which, in turn, requires professional reorientation of employeesВ статье анализируются научные достижения в сфере транспрофессионализма, а также приведены примеры внедрения инноваций в сферу складской логистики, которые приводят к увеличению уровня диверсификации труда, что, в свою очередь, требует профессиональной переориентации работнико

    Near-threshold production of a0(980)a_0(980)-mesons in πN\pi N and NN collisions and a0/f0a_0/f_0-mixing

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    We consider near-threshold a0(980)a_0(980)-meson production in πN\pi N and NNNN collisions. An effective Lagrangian approach with one-pion exchange is applied to analyze different contributions to the cross section for different isospin channels. The Reggeon exchange mechanism is also evaluated for comparison. The results from πN\pi N reactions are used to calculate the contribution of the a0a_0 meson to the cross sections and invariant KKˉK \bar K mass distributions of the reactions pppnK+Kˉ0pp\to pn K^+\bar K^0 and ppppK+Kpp\to pp K^+K^-. It is found that the experimental observation of a0+a_0^+ mesons in the reaction pppnK+Kˉ0pp\to pn K^+\bar K^0 is much more promising than the observation of a00a_0^0 mesons in the reaction ppppK+Kpp\to pp K^+K^-. Effects of isospin violation in the reactions pNda0pN \to d a_0, pd3He/3Ha0pd \to \mathrm{^3He/^3H} a_0, and dd4Hea0 dd \to \mathrm{^4He} a_0, which are induced by a0(980)a_0(980)--f0(980)f_0(980) mixing, are also analyzed.Comment: 43 pages, including 16 eps figures, to be bublished in Phys. Atom. Nucl. (Yad. Fiz.) vol. 65, No. 11 (2002

    Angular asymmetries in the reactions pp \to d\pi^+\eta and pn \to d\pi^0\eta and a_0-f_0 mixing

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    The reactions pp\to d\pi^+\eta and pn\to d\pi^0\eta are of special interest for investigating the a_0(980) (J^P=0^+) resonance in the process NN \to da_0 \to d\pi\eta. We study some aspects of those reactions within a general formalism and also in a concrete phenomenological model. In particular, it is shown that the presence of nonresonant (i.e. without excitation of the a_0 resonance) contributions to these reactions yields nonvanishing values for specific polarization observables, i.e. to effects like those generated by a_0-f_0 mixing. An experimental determination of these observables for the reaction pp\to d\pi^+\eta would provide concrete information on the magnitude of those nonresonant contributions to \pi\eta production. We discuss also the possibility of extracting information about a_0-f_0 mixing from the reaction pn \to d\pi^0\eta with polarized proton beam.Comment: 14 pages, 3 figure

    Aspects of a0-f0 mixing in the reaction pn->da0

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    Some aspects of a0-f0 mixing effects in the reaction pnda00{\vec p} n\to da^0_0 with perpendicular polarized proton beam are discussed. An angular--asymmetry parameter AA is defined to study those effects. It is shown that, for energies close to the production threshold, the angular--asymmetry parameter A(θ,ϕ)A(\theta, \phi) is proportional to the a0-f0 mixing amplitude for arbitrary polar and azimuthal angles θ\theta and ϕ\phi of the outgoing a0a_0 meson. This statement is also valid for arbitrary energies, but then only at polar angles θ=00\theta=0^0 and θ=900\theta=90^0. The mass dependence of the differential cross section dσ/dmπ0ηd\sigma/dm_{\pi^0\eta} in the reaction pndπ0ηpn\to d\pi^0\eta in the presence of \mix mixing is also discussed.Comment: 17 pages, 3 Figure
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