49,244 research outputs found

    On the initial condition for evolution of the perturbative QCD Pomeron in the nucleus

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    It is shown that subdominant terms found in the reggeized gluon diagram technique, to be added to Pomeron fan diagrams with the 3P interaction, can be exactly taken into account by taking the initial condition for evolution in the Glauber form. This demonstrates complete equivalence of the dipole picture and the reggeized gluon approach not only on the leading level but also on the subleading level.Comment: 5 pages in LaTe

    Conformal invariant pomeron interaction in the perurbative QCD with large N_c

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    An effective non-local quantum field theory is constructed, which describes interaction of pomerons in the high-coloured QCD. The theory includes both splitting and merging triple pomeron vertexes and diagrams with pomeronic loops. The Schwinger-Dyson equations for the 'physical' pomeron are written. Conformal invariance allows to reduce the theory to the old-fashioned Gribov pomeron theory with an infinite number of pomerons, one of which is supercritical.Comment: 20 pages in LaTe

    On the inclusive gluon jet production off the nucleus in the perturbative QCD

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    In the perturbative QCD approach single and double inclusive cross-sections for gluon production off the nucleus are studied from the relevant reggeized gluon diagrams. Various terms corresponding to emission of gluons from the triple Pomeron vertex are found. Among them the term derived by Kovchegov and Tuchin emerges as a result of transition from the diffractive to effective high-energy vertex. However it does not exhaust all the vertex contributions to the inclusive cross-section. In the double inclusive cross-section a contribution violating naive AGK rules is found, in which one gluon is emitted from the vertex and the other from one of the Pomerons below the vertex. But then this contribution is subdominant at high energies and taking it into account seems to be questionable.Comment: 22 pages in LaTex, inclusing 7 figure

    ΔπN\Delta\pi N coupling constant in light cone QCD sum rules

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    We employ the light cone QCD sum rules to calculate ΔπN\Delta\pi N coupling constant by studying the two point correlation function between the vacuum and the pion state. Our result is consistent with the traditional QCD sum rules calculations and it is in agreement with the experimental value.Comment: 8 pages, latex, 2 figure

    Production of a gluon with the exchange of three reggeized gluons in the Lipatov effective action approach

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    In the Regge kinematics the amplitude for gluon production off three scattering centers is found in the Lipatov effective action technique. The vertex for gluon emission with the reggeon splitting in three reggeons is calculated and its transversality is demonstrated. It is shown that in the sum of all contributions terms containing principal value singularities are cancelled and substituted by the standard Feynman poles. These results may be used for calculation of the inclusive cross-section for gluon production on two nucleons in the nucleus.Comment: 22 pages, 9 figures; submitted to Eur.Phys.Jour.

    Loops in the gluon emission amplitude: reggeization from the Glauber scattering

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    It is shown that in the Glauber scattering of a fast quark in the external field loop corrections to the gluon emission amplitude due to virtual softer gluon after renormalization coincide with a correction due to reggeization of the exchanged gluon in the BFKL picture.Comment: 26 pages, 10 figure

    Participatory action research on climate risk management, Bangladesh

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    The rural populations of southern Bangladesh are some of the most vulnerable communities in the world to the future impacts of climate change. They are particularly at risk from floods, waterlogged soils, and increasing salinity of both land and water. The objective of this project was to analyze the vulnerability of people in four villages that are experiencing different levels of soil salinity. The study evaluated the strengths and weaknesses of current coping strategies and assessed the potential of an index-based insurance scheme, designed diversification and better information products to improve adaptive capacity

    Double inclusive cross-sections for gluon production in collision of two projectiles on two targets in the BFKL approach

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    Double inclusive cross-sections for gluon production in collision of two nucleons with two nucleons are studied in the BFKL approach. Various contributions include emission from the pomerons attached to the participants, from the BFKL interactions between these pomerons and from the intermediate BKP state. The last contribution may be observable provided the growth with energy of the pomeron contribution is tamed in accordance with unitarity. Possibility of long-range azimuthal correlations due to the BKP state are discussed.Comment: arXiv admin note: substantial text overlap with arXiv:1305.171
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