English
Related papers

Related papers: The Two-Loop Massless Off-Shell QCD Operator Matri…

200 papers

We calculate the unpolarized and polarized three--loop anomalous dimensions and splitting functions $P_{\rm NS}^+, P_{\rm NS}^-$ and $P_{\rm NS}^{\rm s}$ in QCD in the $\overline{\sf MS}$ scheme by using the traditional method of…

High Energy Physics - Phenomenology · Physics 2021-09-15 J. Blümlein , P. Marquard , C. Schneider , K. Schönwald

Future high luminosity polarized deep--inelastic scattering experiments will improve both the knowledge of the spin sub--structure of the nucleons and contribute further to the precision determination of the strong coupling constant, as…

High Energy Physics - Phenomenology · Physics 2022-02-16 J. Blümlein , P. Marquard , C. Schneider , K. Schönwald

We calculate the two-mass three-loop contributions to the unpolarized and polarized massive operator matrix elements $\tilde{A}_{Qg}^{(3)}$ and $\Delta \tilde{A}_{Qg}^{(3)}$ in $x$-space for a general mass ratio by using a semi-analytic…

High Energy Physics - Phenomenology · Physics 2025-10-13 J. Ablinger , 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 the two-loop corrected operator matrix elements calculated in N-dimensional regularization up to the finite terms which survive in the limit $\epsilon = N - 4 \to 0 $. The anomalous dimensions of the local operators have been…

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

We report on the calculation of the three-loop polarized and unpolarized flavor non-singlet and the polarized singlet anomalous dimensions using massless off-shell operator matrix elements in a gauge-variant framework. We also reconsider…

High Energy Physics - Phenomenology · Physics 2022-07-19 J. Blümlein , P. Marquard , C. Schneider , K. Schönwald

The $O(\alpha_s^2)$ massive operator matrix elements for unpolarized and polarized heavy flavor production at asymptotic values $Q^2 >> m^2$ are calculated in Mellin space without applying the integration-by-parts method. We confirm…

High Energy Physics - Phenomenology · Physics 2007-06-20 I. Bierenbaum , J. Blümlein , S. Klein

We present the two-mass QCD contributions to the polarized pure singlet operator matrix element at three loop order in $x$-space. These terms are relevant for calculating the polarized structure function $g_1(x,Q^2)$ at $O(\alpha_s^3)$ as…

High Energy Physics - Phenomenology · Physics 2020-01-15 J. Ablinger , J. Blümlein , A. De Freitas , M. Saragnese , C. Schneider , K. Schönwald

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 report on the three-loop unpolarized and polarized massive operator matrix elements, with single- and two-mass corrections, and the associated deep-inelastic massive Wilson coefficients in the region $Q^2 \gg m_Q^2$, the calculation of…

High Energy Physics - Phenomenology · Physics 2026-02-12 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald

We calculate the gluonic massive operator matrix elements in the unpolarized and polarized cases, $A_{gg,Q}(x,\mu^2)$ and $\Delta A_{gg,Q}(x,\mu^2)$, at three-loop order for a single mass. These quantities contribute to the matching of the…

High Energy Physics - Phenomenology · Physics 2023-01-18 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. Goedicke A. von Manteuffel C. Schneider , K. Schönwald

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

Massive on-shell operator matrix elements and self-energy diagrams with outer gluon lines are calculated analytically at $O(\alpha_s^2)$, using Mellin-Barnes integrals and representations through generalized hypergeometric functions. This…

High Energy Physics - Phenomenology · Physics 2008-11-26 I. Bierenbaum , J. Blümlein , S. Klein

We present a method to calculate the $x$--space expressions of massless or massive operator matrix elements in QCD and QED containing local composite operator insertions, depending on the discrete Mellin index $N$, directly, without…

High Energy Physics - Phenomenology · Physics 2023-07-05 A. Behring , J. Blümlein , K. Schönwald

We present the two-mass QCD contributions to the pure singlet operator matrix element at three loop order in x-space. These terms are relevant for calculating the structure function $F_2(x,Q^2)$ at $O(\alpha_s^3)$ as well as for the…

High Energy Physics - Phenomenology · Physics 2018-02-01 J. Ablinger , J. Blümlein , A. De Freitas , C. Schneider , K. Schönwald

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

We perform the analytic calculation of the Mellin moments of the structure functions F_2 and F_L in perturbative QCD up to second order corrections and in leading twist approximation. We calculate the 2-loop contributions to the anomalous…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. Moch , J. A. M. Vermaseren

We present results on the calculation of the polarized 2- and 3-loop anomalous dimensions in a massive computation of the associated operator matrix element. We also discuss the treatment of $\gamma_5$ and derive results in the M-scheme.10

We report a new result for the $N_f \,C_F^3$ contribution to the four-loop anomalous dimensions of non-singlet, twist-two operators in Quantum Chromodynamics. This result is obtained through computations of off-shell operator matrix…

High Energy Physics - Phenomenology · Physics 2024-12-02 Thomas Gehrmann , Andreas von Manteuffel , Vasily Sotnikov , Tong-Zhi Yang

We discuss a practical approach to compute master integrals entering physical quantities which depend on one parameter. As an example we consider four-loop QCD corrections to the relation between a heavy quark mass defined in the…

High Energy Physics - Phenomenology · Physics 2021-10-11 Matteo Fael , Fabian Lange , Kay Schönwald , Matthias Steinhauser
‹ Prev 1 2 3 10 Next ›