1,606 research outputs found

    On a Possibility to Determine the Sign of the Polarized Gluon Distribution

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    We investigate the possibility to draw conclusions on the sign of the spin-dependent gluon distribution, ΔG(x,Q2)\Delta G(x, Q^2), from existing polarized DIS data. The spin-dependent parton distributions Δuv,Δdv,Δuˉ,Δdˉ,Δs\Delta u_v, \Delta d_v, \Delta {\bar u}, \Delta {\bar d}, \Delta {s}, and ΔG\Delta G are constructed in the framework of a phenomenological procedure taking into account some assumptions on signs of valence and sea parton distributions motivated by 't Hooft's mechanism of quark-quark interaction induced by instantons. The axial gluon anomaly and data on integral quark contributions to the proton spin, Δu~,Δd~\Delta \tilde u, \Delta \tilde d, and Δs~\Delta \tilde s, are also taken into account. Predictions for the xx- and Q2Q^2-dependencies of the polarized proton and neutron structure functions, g1pg_1^p and g1ng_1^n, are compared to experimental data. It is shown that the neutron structure function, g1ng_1^n, is especially sensitive to the sign of ΔG(x,Q2)\Delta G(x, Q^2). The results of our analysis supports the conclusion that this sign should be positive.Comment: 14 pages, latex, 12 figure

    A rationale for some directions of the development of resource territories: the complex ''meso-level'' problem

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    The article presents an approach to the analysis and evaluation of integrated investment projects, which consist of infrastructure facilities and industrial clusters allocated to poorly developed areas rich in natural resources. This study shows the feasibility of a public-private partnership during the construction of infrastructure facilities in order to minimize the risks and maximize the benefits. The conceptual framework of the resulting approach is associated with the ideas and principles of «impact investing» («creation of shared values») and inclusive economic development. These are increasingly used worldwide, especially to accelerate the socio-economic development of backward countries and territories. The article presents an international experience and explains the relevance of best practices in Russia. The authors identified methodological problems associated with the application of traditional methods to the evaluation of economic effects of project investing under the conditions of high uncertainty. The authors explain why it is necessary to use models and methods (real options analysis and fuzzy cognitive models) that allow researchers to directly take into account the uncertainty and project risks. The novelty of the article is the methodological tools for evaluating the socio-economic efficiency of complex projects combining the development of infrastructure and minerals. The proposed approach was used to provide a rationale for a road construction project in the Berezovsky district of the Khanty-Mansi Autonomous Okrug. The authors showed opportunities to generate a set of institutional, organizational, and financial conditions under which the implementation of the project will be attractive to both investors and government and will bring socio-economic benefits to this territory. The proposed approach and tools can be used for a socio-economic strategic decision-making process to justify infrastructure projects in resource-rich regions.The theoretical and methodological results presented in the article were obtained during the research funded by the Russian Science Foundation (Project No. 14–18–02345)
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