2,295 research outputs found

    Numerical Implementation of Harmonic Polylogarithms to Weight w = 8

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    We present the FORTRAN-code HPOLY.f for the numerical calculation of harmonic polylogarithms up to w = 8 at an absolute accuracy of ∼4.9⋅10−15\sim 4.9 \cdot 10^{-15} or better. Using algebraic and argument relations the numerical representation can be limited to the range x∈[0,2−1]x \in [0, \sqrt{2}-1]. We provide replacement files to map all harmonic polylogarithms to a basis and the usual range of arguments x∈]−∞,+∞[x \in ]-\infty,+\infty[ to the above interval analytically. We also briefly comment on a numerical implementation of real valued cyclotomic harmonic polylogarithms.Comment: 19 pages LATEX, 3 Figures, ancillary dat

    Letter from James M. Round to James B. Finley

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    Round writes about the West Wheeling District, Ohio Conference. He reports that work in the district is reviving, and there is definitely some ingathering happening. The labors of William Lamdin, Presiding Elder, have been blessed, and all circuits are in good order. The gentleman delivering this letter is Dr. William Flake, a physician who would like to settle in Finley\u27s county. Round asks Finley to assist Flake if possible. Round asks Finley to give his love to Brother Walker & Sister Hannah. He believes that her relations are in good health. Abstract Number - 43https://digitalcommons.owu.edu/finley-letters/1042/thumbnail.jp

    3-loop Massive O(TF2)O(T_F^2) Contributions to the DIS Operator Matrix Element AggA_{gg}

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    Contributions to heavy flavour transition matrix elements in the variable flavour number scheme are considered at 3-loop order. In particular a calculation of the diagrams with two equal masses that contribute to the massive operator matrix element Agg,Q(3)A_{gg,Q}^{(3)} is performed. In the Mellin space result one finds finite nested binomial sums. In xx-space these sums correspond to iterated integrals over an alphabet containing also square-root valued letters.Comment: 4 pages, Contribution to the Proceedings of QCD '14, Montpellier, July 201

    3-Loop Heavy Flavor Corrections in Deep-Inelastic Scattering with Two Heavy Quark Lines

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    We consider gluonic contributions to the heavy flavor Wilson coefficients at 3-loop order in QCD with two heavy quark lines in the asymptotic region Q2≫m1(2)2Q^2 \gg m_{1(2)}^2. Here we report on the complete result in the case of two equal masses m1=m2m_1 = m_2 for the massive operator matrix element Agg,Q(3)A_{gg,Q}^{(3)}, which contributes to the corresponding heavy flavor transition matrix element in the variable flavor number scheme. Nested finite binomial sums and iterated integrals over square-root valued alphabets emerge in the result for this quantity in NN and xx-space, respectively. We also present results for the case of two unequal masses for the flavor non-singlet OMEs and on the scalar integrals ic case of Agg,Q(3)A_{gg,Q}^{(3)}, which were calculated without a further approximation. The graphs can be expressed by finite nested binomial sums over generalized harmonic sums, the alphabet of which contains rational letters in the ratio η=m12/m22\eta = m_1^2/m_2^2.Comment: 10 pages LATEX, 1 Figure, Proceedings of Loops and Legs in Quantum Field Theory, Weimar April 201

    The 3-Loop Non-Singlet Heavy Flavor Contributions and Anomalous Dimensions for the Structure Function F2(x,Q2)F_2(x,Q^2) and Transversity

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    We calculate the massive flavor non-singlet Wilson coefficient for the heavy flavor contributions to the structure function F2(x,Q2)F_2(x,Q^2) in the asymptotic region Q2≫m2Q^2 \gg m^2 and the associated operator matrix element Aqq,Q(3),NS(N)A_{qq,Q}^{(3), \rm NS}(N) to 3-loop order in Quantum Chromodynamics at general values of the Mellin variable NN. This matrix element is associated to the vector current and axial vector current for the even and the odd moments NN, respectively. We also calculate the corresponding operator matrix elements for transversity, compute the contributions to the 3-loop anomalous dimensions to O(NF)O(N_F) and compare to results in the literature. The 3-loop matching of the flavor non-singlet distribution in the variable flavor number scheme is derived. All results can be expressed in terms of nested harmonic sums in NN space and harmonic polylogarithms in xx-space. Numerical results are presented for the non-singlet charm quark contribution to F2(x,Q2)F_2(x,Q^2).Comment: 82 pages, 3 style files, 33 Figure

    New Results on Massive 3-Loop Wilson Coefficients in Deep-Inelastic Scattering

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    We present recent results on newly calculated 2- and 3-loop contributions to the heavy quark parts of the structure functions in deep-inelastic scattering due to charm and bottom.Comment: Contribution to the Proc. of Loops and Legs 2016, PoS, in prin

    3-loop heavy flavor Wilson coefficients in deep-inelastic scattering

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    We present our most recent results on the calculation of the heavy flavor contributions to deep-inelastic scattering at 3-loop order in the large Q2Q^2 limit, where the heavy flavor Wilson coefficients are known to factorize into light flavor Wilson coefficients and massive operator matrix elements. We describe the different techniques employed for the calculation and show the results in the case of the heavy flavor non-singlet and pure singlet contributions to the structure function F2(x,Q2)F_2(x,Q^2).Comment: 4 pages Latex, 2 style files, 4 Figures, Contribution to the Proceedings of QCD '14, Montpellier, Jult 201

    Recent progress on the calculation of three-loop heavy flavor Wilson coefficients in deep-inelastic scattering

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    We report on our latest results in the calculation of the three-loop heavy flavor contributions to the Wilson coefficients in deep-inelastic scattering in the asymptotic region Q2≫m2Q^2 \gg m^2. We discuss the different methods used to compute the required operator matrix elements and the corresponding Feynman integrals. These methods very recently allowed us to obtain a series of new operator matrix elements and Wilson coefficients like the flavor non-singlet and pure singlet Wilson coefficients.Comment: 11 pages Latex, 2 Figures, Proc. of Loops and Legs in Quantum Field Theory, April 2014, Weimar, German

    Coordination of tolerogenic immune responses by the commensal microbiota

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    All mammals are born ignorant to the existence of micro-organisms. Soon after birth, however, every mammal begins a lifelong association with a multitude of microbes that lay residence on the skin, mouth, vaginal mucosa and gastrointestinal (GI) tract. Approximately 500–1000 different species of microbes have highly evolved to occupy these bodily niches, with the highest density and diversity occurring within the intestine [1]. These organisms play a vital role in mammalian nutrient breakdown and provide resistance to colonization by pathogenic micro-organisms. More recently, however, studies have demonstrated that the microbiota can have a profound and long-lasting effect on the development of our immune system both inside and outside the intestine [2]. While our immune system has evolved to recognize and eradicate foreign entities, it tolerates the symbiotic micro-organisms of the intestine. How and why this tolerance occurs has remained unclear. Here we present evidence that the commensal microbes of the intestine actively induce tolerant responses from the host that coordinate healthy immune responses. Potentially, disruption of this dialogue between the host and microbe can lead to the development of autoimmune diseases such as inflammatory bowel disease (IBD), rheumatoid arthritis (RA), or Type I diabetes (TID). As a wealth of publications have focused on the impact of the microbiota on intestinal immune responses and IBD, this chapter will focus on the extra-intestinal impacts of the microbiota from development to disease and integrate the known mechanisms by which the microbiota is able to actively communicate with its host to promote health
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