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We present the computation of a full set of planar five-point two-loop master integrals with one external mass. These integrals are an important ingredient for two-loop scattering amplitudes for two-jet-associated W-boson production at…

High Energy Physics - Phenomenology · Physics 2020-12-30 S. Abreu , H. Ita , F. Moriello , B. Page , W. Tschernow , M. Zeng

We present a technique which permits the calculation of two-point functions of operators containing one heavy quark and an arbitrary number of light quarks as analytic functions of the heavy-quark mass. It is based on the standard Jacobi…

High Energy Physics - Lattice · Physics 2010-11-01 D. S. Henty , R. D. Kenway

We explore single and multi-loop conformal integrals, such as the ones appearing in dual conformal theories in flat space. Using Mellin amplitudes, a large class of higher loop integrals can be written as simple integro-differential…

High Energy Physics - Theory · Physics 2015-06-12 Dhritiman Nandan , Miguel F. Paulos , Marcus Spradlin , Anastasia Volovich

Three loop ladder and $V$-topology diagrams contributing to the massive operator matrix element $A_{Qg}$ are calculated. The corresponding objects can all be expressed in terms of nested sums and recurrences depending on the Mellin variable…

High Energy Physics - Phenomenology · Physics 2016-04-20 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider

3-loop diagrams of the ladder-type, which emerge for local quarkonic twist-2 operator matrix elements, are computed directly for general values of the Mellin variable $N$ using Appell-function representations and applying modern summation…

High Energy Physics - Phenomenology · Physics 2015-06-05 Jakob Ablinger , Johannes Blümlein , Alexander Hasselhuhn , Sebastian Klein , Carsten Schneider , Fabian Wißbrock

Recent developments in the computation of two-loop master integrals for massive Bhabha scattering are briefly reviewed. We apply a method based on expansions of exact Mellin-Barnes representations and evaluate all planar four-point master…

High Energy Physics - Phenomenology · Physics 2009-11-11 Stefano Actis , Michal Czakon , Janusz Gluza , Tord Riemann

We compute the two-loop master integrals for leading-color QCD scattering amplitudes including a closed light-quark loop in $t\bar{t}H$ production at hadron colliders. Exploiting numerical evaluations in modular arithmetic, we construct a…

High Energy Physics - Phenomenology · Physics 2024-07-18 F. Febres Cordero , G. Figueiredo , M. Kraus , B. Page , L. Reina

We introduce techniques to treat numerically Mellin-Barnes integrals in physical regions, which arise in the need of the computation of Feynman integrals for the electroweak two-loop corrections to the pseudo observables at the Z-boson…

High Energy Physics - Phenomenology · Physics 2018-10-11 Johann Usovitsch , Ievgen Dubovyk , Tord Riemann

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 complete the calculation of master integrals for massless three-loop form factors by computing the previously-unknown three diagrams with nine propagators in dimensional regularisation. Each of the integrals yields a six-fold…

High Energy Physics - Phenomenology · Physics 2009-07-24 G. Heinrich , T. Huber , D. A. Kosower , V. A. Smirnov

We compute the two-loop crossed six-line vertex master integral with two massive lines in dimensional regularisation, and give the result up to the finite part in D-4. We focus in particular on the purely analytical calculation of the…

High Energy Physics - Phenomenology · Physics 2009-03-27 T. Huber

The calculation of massive 2--loop operator matrix elements, required for the higher order Wilson coefficients for heavy flavor production in deeply inelastic scattering, leads to new types of multiple infinite sums over harmonic sums and…

Mathematical Physics · Physics 2008-12-18 I. Bierenbaum , J. Blümlein , S. Klein , C. Schneider

Starting at 3-loop order, the massive Wilson coefficients for deep-inelastic scattering and the massive operator matrix elements describing the variable flavor number scheme receive contributions of Feynman diagrams carrying quark lines…

High Energy Physics - Phenomenology · Physics 2017-08-23 J. Ablinger , J. Blümlein , A. De Freitas , A. Hasselhuhn , C. Schneider , F. Wißbrock

We compute the master integrals containing 2 and 3 massive propagators entering the planar amplitudes of the 2-loop electroweak form factor. The masses of the $W$, $Z$ and Higgs bosons are assumed to be degenerate. This work is a…

High Energy Physics - Phenomenology · Physics 2009-11-10 U. Aglietti , R. Bonciani

We introduce in typical examples new methods for the calculation of massive loop integrals appearing in the radiative correction calculations of the Standard Model.

High Energy Physics - Phenomenology · Physics 2011-04-20 Dirk Kreimer

We determine the master integrals for vertex and propagator diagrams that appear in effective field theories containing heavy fields. The integrals involve at least one heavy line, and the standard lines include an arbitrary mass scale. The…

High Energy Physics - Phenomenology · Physics 2022-01-19 B. Assi , B. A. Kniehl , A. I. Onishchenko

We compute the logarithmic contributions to the polarized massive Wilson coefficients for deep-inelastic scattering in the asymptotic region $Q^2 \gg m^2$ to 3-loop order in the fixed-flavor number scheme and present the corresponding…

High Energy Physics - Phenomenology · Physics 2021-09-08 J. Blümlein , A. De Freitas , M. Saragnese , C. Schneider , K. Schönwald

We discuss the Mellin-Barnes representation of complex multidimensional integrals. Experiments frontiered by the High-Luminosity Large Hadron Collider at CERN and future collider projects demand the development of computational methods to…

High Energy Physics - Phenomenology · Physics 2022-11-28 Ievgen Dubovyk , Janusz Gluza , Gabor Somogyi

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 highlight the latest developments in computing higher-order scattering amplitudes with massive internal propagators. The contributing Feynman integrals often lead to special classes of functions, for example, functions associated with…

High Energy Physics - Phenomenology · Physics 2022-07-26 Ekta Chaubey