268 research outputs found

    Higher Mellin moments for charged current DIS

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    We report on our recent results for deep-inelastic neutrino-proton scattering. We have computed the perturbative QCD corrections to three loops for the harged current structure functions F_2, F_L and F_3 for the combination nu P - nubar P. In leading twist approximation we have calculated the first six odd-integer Mellin moments in the case of F_2 and F_L and the first six even-integer moments in the case of F_3. As a new result we have obtained the coefficient functions to O(alpha_s^3) and we have found the corresponding anomalous dimensions to agree with known results in the literature.Comment: Contribution to the proceedings of the conference DIS 2007, Munich, April 200

    Laurent series expansion of a class of massive scalar one-loop integrals up to {\cal O}(\ep^2) in terms of multiple polylogarithms

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    In a recent paper we have presented results for a set of massive scalar one-loop master integrals needed in the NNLO parton model description of the hadroproduction of heavy flavors. The one--loop integrals were evaluated in n=4-2\ep dimension and the results were presented in terms of a Laurent series expansion up to {\cal O}(\ep^2). We found that some of the \ep^2 coefficients contain a new class of functions which we termed the LL functions. The LL functions are defined in terms of one--dimensional integrals involving products of logarithm and dilogarithm functions. In this paper we derive a complete set of algebraic relations that allow one to convert the LL functions of our previous approach to a sum of classical and multiple polylogarithms. Using these results we are now able to present the \ep^2 coefficients of the one-loop master integrals in terms of classical and multiple polylogarithms.Comment: 32 pages, Latex, references added, matches published versio

    Next-to-next-to-leading order O(αs4){\cal O}(\alpha_s^4) results for heavy quark pair production in quark--antiquark collisions: The one-loop squared contributions

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    We calculate the next-to-next-to-leading order O(αs4){\cal O}(\alpha_s^4) one-loop squared corrections to the production of heavy quark pairs in quark-antiquark annihilations. These are part of the next-to-next-to-leading order O(αs4){\cal O}(\alpha_s^4) radiative QCD corrections to this process. Our results, with the full mass dependence retained, are presented in a closed and very compact form, in the dimensional regularization scheme. We have found very intriguing factorization properties for the finite part of the amplitudes.Comment: 12 pages, 2 figures, electronic results file, abbreviation NNLO in Title and Abstract expanded, Summary expanded, reference updated, version to appear in Phys.Rev.

    One-loop amplitudes for four-point functions with two external massive quarks and two external massless partons up to O(epsilon^2)

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    We present complete analytical O(ϵ2){\mathcal O}(\epsilon^2) results on the one-loop amplitudes relevant for the NNLO quark-parton model description of the hadroproduction of heavy quarks as given by the so-called loop-by-loop contributions. All results of the perturbative calculation are given in the dimensional regularization scheme. These one-loop amplitudes can also be used as input in the determination of the corresponding NNLO cross sections for heavy flavor photoproduction, and in photon-photon reactions.Comment: 25 pages, 6 figures in the text, Revtex, one reference added, minor improvements in the text, to appear in Phys.Rev.

    CO oxidation at Pd(100): A first-principles constrained thermodynamics study

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    The possible formation of oxides or thin oxide films (surface oxides) on late transition metal surfaces is recently being recognized as an essential ingredient when aiming to understand catalytic oxidation reactions under technologically relevant gas phase conditions. Using the CO oxidation at Pd(100) as example, we investigate the composition and structure of this model catalyst surface over a wide range of (T,p)-conditions within a multiscale modeling approach where density-functional theory is linked to thermodynamics. The results show that under the catalytically most relevant gas phase conditions a thin surface oxide is the most stable "phase" and that the system is actually very close to a transition between this oxidic state and a reduced state in form of a CO covered Pd(100) surface.Comment: 13 pages including 7 figures; related publications can be found at http://www.fhi-berlin.mpg.de/th/th.htm

    Kinetic hindrance during the initial oxidation of Pd(100) at ambient pressures

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    The oxidation of the Pd(100) surface at oxygen pressures in the 10^-6 to 10^3 mbar range and temperatures up to 1000 K has been studied in-situ by surface x-ray diffraction (SXRD). The results provide direct structural information on the phases present in the surface region and on the kinetics of the oxide formation. Depending on the (T,p) environmental conditions we either observe a thin sqrt(5) x sqrt(5) R27 surface oxide or the growth of a rough, poorly ordered bulk oxide film of PdO predominantly with (001) orientation. By either comparison to the surface phase diagram from first-principles atomistic thermodynamics or by explicit time-resolved measurements we identify a strong kinetic hindrance to the bulk oxide formation even at temperatures as high as 675 K.Comment: 4 pages including 4 figures, Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

    О КЛИНИЧЕСКОЙ РАБОТЕ НИИ СП ИМ. Н.В. СКЛИФОСОВСКОГО

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    About clinical work in Sklifosovsky Research Institute for Emergency Medicine.Мы поинтересовались мнением заместителя директора НИИ СП им. Н.В. Склифосовского по лечебной работе — главным врачом института профессором М.Л. Рогалем о настоящем состоянии клинической деятельности института

    О ЛЕЧЕБНОЙ РАБОТЕ НИИ СКОРОЙ ПОМОЩИ ИМ. Н.В. СКЛИФОСОВСКОГО В 2013 ГОДУ

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    About clinical work in Sklifosovsky research Institute for Emergency Medicine in 2013.Представляем Вашему вниманию мнение заместителя директора по лечебной работе НИИ СП им. Н.В. Склифосовского — главного врача института профессора Михаила Леонидовича Рогаля о лечебной работе НИИ скорой помощи им. Н.В. Склифосовского в 2013 году

    Opioid prescriptions are associated with hepatic encephalopathy in a national cohort of patients with compensated cirrhosis

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154367/1/apt15639_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154367/2/apt15639.pd
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