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Related papers: Evaluating Two-Loop massive Operator Matrix Elemen…

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We present a factorized decomposition of 4-point scalar conformal blocks near the lightcone, which applies to arbitrary intermediate spin and general spacetime dimensions. Then we discuss the systematic expansion in large intermediate spin…

High Energy Physics - Theory · Physics 2021-05-20 Wenliang Li

A number of irreducible master integrals for L-loop sunrise-type and bubble Feynman diagrams with generic values of masses and external momenta are explicitly evaluated via Mellin-Barnes representation.

High Energy Physics - Theory · Physics 2017-08-02 Mikhail Yu. Kalmykov , Bernd A. Kniehl

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 develop a method to obtain $\epsilon$-expansions of massless two-point integrals in position space, based on the constraints implied by symmetries of the asymptotic expansion of conformal four-point integrals. Together with parametric…

High Energy Physics - Theory · Physics 2018-02-05 Alessandro Georgoudis , Vasco Gonçalves , Erik Panzer , Raul Pereira

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

Multi-loop integrals can be evaluated numerically using Mellin-Barnes representations. Here this technique is applied to the calculation of electroweak two-loop correction with closed fermion loops for two observables: the effective weak…

High Energy Physics - Phenomenology · Physics 2013-10-14 A. Freitas , Yi-Cheng Huang

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 obtain for the first time the two-loop amplitudes for Higgs plus three gluons in Higgs effective field theory including dimension-seven operators. This provides the S-matrix elements for the top mass corrections for Higgs plus a jet…

High Energy Physics - Theory · Physics 2018-09-11 Qingjun Jin , Gang Yang

We present the analytic computation of all the planar master integrals which contribute to the two-loop scattering amplitudes for Higgs$\to 3$ partons, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to…

High Energy Physics - Phenomenology · Physics 2017-02-01 Roberto Bonciani , Vittorio Del Duca , Hjalte Frellesvig , Johannes M. Henn , Francesco Moriello , Vladimir A. Smirnov

We consider the case of a two-loop five-point pentagon-box integral configuration with one internal massive propagator that contributes to top-quark pair production in association with a jet at hadron colliders. We construct the system of…

High Energy Physics - Phenomenology · Physics 2023-03-31 Simon Badger , Matteo Becchetti , Ekta Chaubey , Robin Marzucca

This article displays a proof of concept of the mixed analytical/numerical method, presented in previous publications, to compute two-loop functions with up to five massive propagators in a scalar theory having three- and four-leg vertices…

High Energy Physics - Phenomenology · Physics 2021-09-15 J. Ph. Guillet , E. Pilon , Y. Shimizu , M. S. Zidi

We compute the full set of two-loop Feynman integrals appearing in massless two-loop four-point functions with two off-shell legs with the same invariant mass. These integrals allow to determine the two-loop corrections to the amplitudes…

High Energy Physics - Phenomenology · Physics 2014-06-13 Thomas Gehrmann , Andreas von Manteuffel , Lorenzo Tancredi , Erich Weihs

We compute scalar three-point celestial amplitudes involving two and three massive scalars. The three-point coefficient of celestial amplitudes with two massive scalars contains a hypergeometric function, and the one with three massive…

High Energy Physics - Theory · Physics 2025-12-16 Reiko Liu , Wen-Jie Ma

We compute angular phase-space integrals with three and four denominators analytically, working within dimensional regularisation via the Mellin-Barnes (MB) representation. The approach converts multifold MB integrals into real parametric…

High Energy Physics - Phenomenology · Physics 2026-04-03 Taushif Ahmed , Syed Mehedi Hasan , Andreas Rapakoulias

We describe the calculation of the two--loop massive operator matrix elements for massive external fermions. These matrix elements are needed for the calculation of the $O(\alpha^2)$ initial state radiative corrections to $e^+e^-$…

High Energy Physics - Phenomenology · Physics 2009-04-14 J. Blümlein , A. De Freitas , W. van Neerven

We construct a functional model (direct integral expansion) and study the spectra of certain periodic block-operator Jacobi matrices, in particular, of general 2D partial difference operators of the second order. We obtain the upper bound,…

Spectral Theory · Mathematics 2019-07-03 Leonid Golinskii , Anton Kutsenko

Recent results on the calculation of 3-loop massive operator matrix elements in case of one and two heavy quark masses are reported. They concern the $O(n_f T_F^2 C_{F,A})$ and $O(T_F^2 C_{F,A})$ gluonic corrections, two-mass quarkonic…

High Energy Physics - Phenomenology · Physics 2016-08-14 J. Ablinger , J. Blümlein , A. De Freitas , A. Hasselhuhn , S. Klein , C. Raab , M. Round , C. Schneider , F. Wißbrock

We address the problem of evaluation of multiloop Feynman integrals by means of their Mellin-Barnes representation. After a brief overview of available capabilities though open source toolkits and their application in various circumstances,…

High Energy Physics - Phenomenology · Physics 2023-01-25 A. V. Belitsky , A. V. Smirnov , V. A. Smirnov

Feynman diagrams may be evaluated by Mellin-Barnes representations of their Feynman parameter integrals in d=4-2\eps dimensions. Recently, the Mathematica toolkit AMBRE has been developed for the automatic derivation of such representations…

High Energy Physics - Phenomenology · Physics 2009-04-16 J. Gluza , F. Haas , K. Kajda , T. Riemann

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