152,318 research outputs found

    Double Q2Q^2-rescaling model and the nuclear effect of the parton distribution functions

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    In order to overcome the shortcoming of nonconservation of nuclear momentum existing in the original Q2Q^2-rescaling model(OQ2Q^2RM) and avoid introducing nuclear shadowing factor, we proposed a double Q2Q^2-rescaling model(DQ2Q^2RM) for the parton distributions of the bound nucleon. Using the experimental data of lepton-nucleus deep inelastic scattering(DIS) and the condition of the nuclear momentum conservation, the Q2Q^2-rescaling parameters of various partons for Sn, Fe, Ca and C nuclei are determined. The rescaling parameters of valence quark distributions are larger than unity and graduauly increases with atomic number A, on the contrary, the rescaling parameters of sea quark distributions and gluon distributions are smaller than unity, and slowly decreases with A. By using this model, the experimental data of the DIS process, the nuclear Drell-Yan process and J/ψJ/\psi photoproduction process are consistently and quite satisfactorily explained. Key words --- parton distribution functions, Nuclear effect, Double Q2Q^2-rescaling model.Comment: 15 pages, 4 figures (to be published in Z. Phys. C

    Rescaling limits of complex rational maps

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    We discuss rescaling limits for sequences of complex rational maps in one variable which approach infinity in parameter space.It is shown that any given sequence of maps of degree d2d \ge 2 has at most 2d22d-2 dynamically distinct rescaling limits which are not postcritically finite. For quadratic rational maps, a complete description of the possible rescaling limits is given. These results are obtained employing tools from non-Archimedean dynamics

    Unveiling vertical state downscaling: identity and/or the economy?

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    State rescaling may take a variety of shapes although scant research has been carried out into the mechanisms and economic incentives that underpin rescaling processes. Recent literature in economics, economic sociology and political economy has identified at least two broad rescaling mechanisms, namely the development of regional identity - operating at the cultural level and proxing preference heterogeneity-, and the heterogeneity in levels of economic development, which influence the extent of regional redistribution. This paper empirically examines the mechanisms of vertical state rescaling by drawing upon empirical evidence from Catalonia and the Basque Country, to explore the evolution of sub-state identity and the rise of inter-territorial fiscal grievances - weakening intraregional economic solidarity. Findings corroborate the idea that the combination of widening sub-national identity raises the costs of managing heterogeneous spatial identities and strengthens support for vertical state downscaling. Similarly, ending regional fiscal solidarity it is found to increase the average income of Catalonia by 37% and even 17% in the Basque Country. However, the effect of regional identity exceeds that of regional redistribution in explaining state rescaling support in the magnitude of one to seven. These findings speak to the debate on the formation of Europe, in that they reveal limits to regional redistribution and highlight the importance of a common spatial identity

    Analytical Rescaling of Polymer Dynamics from Mesoscale Simulations

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    We present a theoretical approach to scale the artificially fast dynamics of simulated coarse-grained polymer liquids down to its realistic value. As coarse-graining affects entropy and dissipation, two factors enter the rescaling: inclusion of intramolecular vibrational degrees of freedom, and rescaling of the friction coefficient. Because our approach is analytical, it is general and transferable. Translational and rotational diffusion of unentangled and entangled polyethylene melts, predicted from mesoscale simulations of coarse-grained polymer melts using our rescaling procedure, are in quantitative agreement with united atom simulations and with experiments.Comment: 6 pages, 2 figures, 2 table

    Rescaling of Nuclear Structure Functions

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    It is shown that nucleonic structure functions are xx- and Q2Q^{2}-rescaled in nuclei. The xx-rescaling accounts for nuclear effects in the case of exact scaling, while the Q2Q^{2}-rescaling is responsible for a corresponding modification of quantum corrections. This result is obtained in the leading order for all flavour combinations and connects the two known models for the EMC-effect. Electroproduction and gluonic nuclear structure functions are calculated.Comment: 9 pages, Latex, 2 figures appended (compressed and uuencoded