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The two-loop QCD corrections to vector boson pair production at hadron colliders involve a new class of Feynman integrals: two-loop four-point functions with two off-shell external legs. We describe their reduction to a small set of master…

High Energy Physics - Phenomenology · Physics 2013-08-26 Thomas Gehrmann , Lorenzo Tancredi , Erich Weihs

We discuss an algorithm for the numerical evaluation of NLO multiparton processes. We focus hereby on the virtual part of the NLO calculation, i.e. on evaluating the one-loop integration numerically. We employ and extend the ideas of the…

High Energy Physics - Phenomenology · Physics 2012-09-14 S. Becker , D. Goetz , C. Reuschle , C. Schwan , S. Weinzierl

We present algorithms to work with iterated Eisenstein integrals that have recently appeared in the computation of multi-loop Feynman integrals. These algorithms allow one to analytically continue these integrals to all regions of the…

High Energy Physics - Theory · Physics 2020-03-18 Claude Duhr , Lorenzo Tancredi

We perform the integration of all iterated singly-unresolved subtraction terms, as defined in ref. [1], over the two-particle factorized phase space. We also sum over the unresolved parton flavours. The final result can be written as a…

High Energy Physics - Phenomenology · Physics 2011-05-10 Paolo Bolzoni , Gabor Somogyi , Zoltan Trocsanyi

We present an algorithm to compute arbitrary multi-loop massive Feynman diagrams in the region where the typical energy scale \sqrt{s} is much larger than the typical mass scale M, i.e. s>>M^2, while various different energy and mass…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Denner , S. Pozzorini

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 loop-by-loop method for computing the differential equations of Feynman integrals using the recently developed dual form formalism. We give explicit prescriptions for the loop-by-loop fibration of multi-loop dual forms. Then,…

High Energy Physics - Theory · Physics 2023-03-23 Mathieu Giroux , Andrzej Pokraka

We present an algorithm for the numerical calculation of one-loop QCD amplitudes. The algorithm consists of subtraction terms, approximating the soft, collinear and ultraviolet divergences of one-loop amplitudes and a method to deform the…

High Energy Physics - Phenomenology · Physics 2010-12-09 Sebastian Becker , Christian Reuschle , Stefan Weinzierl

The ideas behind the concept of algebraic ("integration-by-parts") algorithms for multiloop calculations are reviewed. For any topology and mass pattern, a finite iterative algebraic procedure is proved to exist which transforms the…

High Energy Physics - Phenomenology · Physics 2011-04-15 Fyodor V. Tkachov

We introduce a new approach for the computation of the class of Feynman integrals whose integrands vanish in strictly four-dimensions, so-called ''pseudo-evanescent'' integrals. We argue that, up to $\mathcal{O}(\epsilon)$ corrections,…

High Energy Physics - Theory · Physics 2026-05-06 Alessandro Georgoudis , Ben Page

A new integration technique for multi-loop Feynman integrals, called the matrix method, is developed and then applied to the divergent part of the overlapping two-loop quark self-energy function $\,i\Sigma\,$ in the light- cone gauge. It is…

High Energy Physics - Theory · Physics 2009-10-28 George Leibbrandt , Jimmy Williams

Canonical Feynman integrals are of great interest in the study of scattering amplitudes at the multi-loop level. We propose to construct $d\log$-form integrals of the hypergeometric type, treat them as a representation of Feynman integrals,…

High Energy Physics - Theory · Physics 2021-02-03 Jiaqi Chen , Xuhang Jiang , Xiaofeng Xu , Li Lin Yang

We determine the complete three-loop QCD soft anomalous dimension for multileg amplitudes involving a single massive coloured particle and any number of massless ones. This is achieved by applying a novel strategy based on a lightcone…

High Energy Physics - Phenomenology · Physics 2025-11-03 Einan Gardi , Zehao Zhu

In this paper, we describe a numerical approach to evaluate Feynman loop integrals. In this approach the key technique is a combination of a numerical integration method and a numerical extrapolation method. Since the computation is carried…

High Energy Physics - Phenomenology · Physics 2011-09-21 F. Yuasa , T. Ishikawa , Y. Kurihara , J. Fujimoto , Y. Shimizu , N. Hamaguchi , E. de Doncker , K. Kato

We invent an automated method for computing the divergent part of Feynman integrals in dimensional regularization. Our method exploits simplifications from four-dimensional integration-by-parts identities. Leveraging algorithms from the…

High Energy Physics - Theory · Physics 2023-09-19 Johannes Henn , Rourou Ma , Kai Yan , Yang Zhang

We review the method of the calculation of multiloop integrals recently suggested in Ref.[Lee2010]. A simple method of derivation of the dimensional recurrence relation suitable for automatization is given. Some new analytic results are…

High Energy Physics - Phenomenology · Physics 2010-12-13 R. N. Lee

We present a first numerical implementation of the Loop-Tree Duality (LTD) method for the direct numerical computation of multi-leg one-loop Feynman integrals. We discuss in detail the singular structure of the dual integrands and define a…

High Energy Physics - Phenomenology · Physics 2015-10-06 Sebastian Buchta , Grigorios Chachamis , Petros Draggiotis , German Rodrigo

We show that, by viewing a 4D effective-field theory as the infrared (IR) limit of the compactified version in 5D, we can compute two-loop anomalous dimensions without gauge-breaking counter-terms, IR re-arrangement or geometric methods.…

High Energy Physics - Phenomenology · Physics 2025-12-04 Mikael Chala , Javier López Miras

A framework to represent and compute two-loop $N$-point Feynman diagrams as double-integrals is discussed. The integrands are 'generalised one-loop type" multi-point functions multiplied by simple weighting factors. The final integrations…

High Energy Physics - Phenomenology · Physics 2020-04-15 J. Ph. Guillet , E. Pilon , Y. Shimizu , M. S. Zidi

NLO scattering amplitudes are provided by fully automated numerical tools, such as OpenLoops, for a very wide range of processes. In order to match the numerical precision of current and future collider experiments, the higher precision of…

High Energy Physics - Phenomenology · Physics 2022-07-18 Stefano Pozzorini , Natalie Schär , Max F. Zoller