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Related papers: Two-Loop Massive Operator Matrix Elements for Pola…

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We report on progress in the calculation of 3-loop corrections to the deep-inelastic structure functions from massive quarks in the asymptotic region of large momentum transfer $Q^2$. Recently completed results allow us to obtain the…

We report on the first analytic NNLL calculation for the matrix elements of the operators O_1 and O_2 for the inlusive process b --> X_s l^+l^- in the kinematical region q^2>4m_c^2, where q^2 is the invariant mass squared of the…

High Energy Physics - Phenomenology · Physics 2014-11-20 Volker Pilipp , Christof Schupbach

We calculate the Mellin moments of the $O(\alpha_s^2)$ coefficient functions for the unpolarized and polarized fragmentation functions. They can be expressed in terms of multiple finite harmonic sums of maximal weight {\sf w = 4}. Using…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Blümlein , V. Ravindran

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 $Q^2 \gg m_{1(2)}^2$. Here we report on the complete result in the case of two equal masses…

High Energy Physics - Phenomenology · Physics 2014-07-11 J. Ablinger , J. Blümlein , A. De Freitas , A. Hasselhuhn , A. von Manteuffel , M. Round , C. Schneider , F. Wißbrock

The non-first-order-factorizable contributions (The terms 'first-order-factorizable contributions' and 'non-first-order-factorizable contributions' have been introduced and discussed in Refs. \cite{Behring:2023rlq,Ablinger:2023ahe}. They…

High Energy Physics - Phenomenology · Physics 2024-05-15 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald

We discuss how the operator product expansion (OPE) can be used to derive asymptotic expressions for certain integrals. This yields operator matrix elements (OME's) which determine the matching conditions for $\bar{\rm MS}$ parton densities…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Smith

We describe the calculation of the two--loop massive operator matrix elements with massive external fermions in QED. We investigate the factorization of the $O(\alpha^2)$ initial state corrections to $e^+e^-$ annihilation into a virtual…

High Energy Physics - Phenomenology · Physics 2011-11-29 J. Blümlein , A. De Freitas , W. L. van Neerven

This thesis is concerned with the calculation of fixed moments of the O(a_s^3) heavy flavor contributions to the Wilson coefficients of the structure function F_2(x,Q^2) in the limit Q^2 >> m^2, neglecting power corrections. The massive…

High Energy Physics - Phenomenology · Physics 2009-10-19 Sebastian Klein

We present the two-loop corrected operator matrix elements contributing to the scale evolution of the longitudinal spin structure function $g_1(x,Q^2)$ calculated up to finite terms which survive in the limit $\epsilon = N - 4 \to 0$. These…

High Energy Physics - Phenomenology · Physics 2009-10-31 Y. Matiounine , J. Smith , W. L. van Neerven

We calculate moments of the $O(\alpha_s^3)$ heavy flavor contributions to the Wilson coefficients of the structure function $F_2(x,Q^2)$ in the region $Q^2\gg m^2$. The massive Wilson coefficients are obtained as convolutions of massive…

High Energy Physics - Phenomenology · Physics 2014-11-20 Isabella Bierenbaum , Johannes Blümlein , Sebastian Klein

In this paper, we compute the first set of ${\cal O}(\alpha_s^2)$ corrections to semi-inclusive deep inelastic scattering structure functions. We start by studying the impact of the contribution of the partonic subprocesses that open at…

High Energy Physics - Phenomenology · Physics 2017-03-01 Daniele Anderle , Daniel de Florian , Yamila Rotstein Habarnau

Critical exponents are computed for a variety of twist-2 composite operators, which occur in polarized and unpolarized deep inelastic scattering, at leading order in the 1/N_f expansion. The resulting d-dimensional expressions, which depend…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. A. Gracey

We calculate non-singlet quark operator matrix elements of deep-inelastic scattering in the chiral limit including operators with total derivatives. This extends previous calculations with zero-momentum transfer through the operator vertex…

High Energy Physics - Phenomenology · Physics 2021-09-14 S. Moch , S. Van Thurenhout

We calculate the massive polarized three-loop pure singlet operator matrix element $A_{Qq}^{(3), \rm PS}$ in the single mass case in the Larin scheme. This operator matrix element contributes to the massive polarized three-loop Wilson…

High Energy Physics - Phenomenology · Physics 2020-02-12 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald

We calculate all contributions $\propto T_F$ to the polarized three-loop anomalous dimensions in the M-scheme using massive operator matrix elements and compare to results in the literature. This includes the complete anomalous dimensions…

High Energy Physics - Phenomenology · Physics 2019-09-25 A. Behring , J. Blümlein , A. De Freitas , A. Goedicke , S. Klein , A. von Manteuffel , C. Schneider , K. Schönwald

We present recent analytic results for the 3-loop corrections to the massive operator matrix element $A_{Qg}^{(3)}$for further color factors. These results have been obtained using the method of arbitrarily large moments. We also give an…

High Energy Physics - Phenomenology · Physics 2017-11-22 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider

We compute Mellin moments of the heavy-quark structure functions in deep-inelastic scattering at next-to-leading order in quantum chromodynamics, retaining their full dependence on the heavy-quark mass. Using the optical theorem and the…

High Energy Physics - Phenomenology · Physics 2026-02-06 Marco Klann , Sven-Olaf Moch , Kay Schönwald

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 $Q^2$ limit, where the heavy flavor Wilson coefficients are known to factorize into light…

High Energy Physics - Phenomenology · Physics 2014-09-08 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. Hasselhuhn , A. von Manteuffel , C. Raab , M. Round , S. Schneider , F. Wißbrock

We report on recent results on the two-mass corrections for massive operator matrix elements at 2- and 3-loop orders in QCD. These corrections form the building blocks of the variable flavor number scheme. Due to the similar values of the…

High Energy Physics - Phenomenology · Physics 2018-07-23 J. Ablinger , J. Blümlein , A. De Freitas , A. Goedicke , C. Schneider , K. Schönwald

We report on recent progress in the calculation of the 3-loop massive Wilson coefficients in deep-inelastic scattering at general values of $N$ for neutral and charged current reactions in the asymptotic region $Q^2 \gg m^2$. Four new out…

High Energy Physics - Phenomenology · Physics 2013-12-03 A. Behring , J. Blümlein , A. De Freitas , T. Pfoh , C. Raab , M. Round , J. Ablinger , A. Hasselhuhn , C. Schneider , F. Wißbrock , A. von Manteuffel