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Related papers: Two-loop Six-point Planar Massless Feynman Integra…

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The computation of Feynman integrals is often the bottleneck of multi-loop calculations. We propose and implement a new method to efficiently evaluate such integrals in the physical region through the numerical integration of a suitable set…

High Energy Physics - Phenomenology · Physics 2019-05-01 Manoj K. Mandal , Xiaoran Zhao

We obtain for the first time the analytic two-loop four-point MHV lightlike form factor of the stress-tensor supermultiplet in planar ${\cal N}=4$ SYM where the momentum $q$ carried by the operator is taken to be massless. Remarkably, we…

High Energy Physics - Theory · Physics 2025-03-11 Yuanhong Guo , Lei Wang , Gang Yang

Motivated by the precision results in the electroweak theory studies of two-loopFeynman diagrams are performed. Specifically this paper gives a contribution to the knowledge of massive two-loop self-energy diagrams in arbitrary and…

High Energy Physics - Phenomenology · Physics 2011-09-30 S. Bauberger , F. A. Berends , M. Boehm , M. Buza

We study the six-particle amplitude in planar $\mathcal{N} = 4$ super Yang-Mills theory in the double scaling (DS) limit, the only nontrivial codimension-one boundary of its positive kinematic region. We construct the relevant function…

High Energy Physics - Theory · Physics 2023-02-22 Vsevolod Chestnov , Georgios Papathanasiou

We calculate analytically the two-loop triangle integrals entering the $\mathcal{O}(\alpha\alpha_s)$ corrections to the $HZV$ vertex with $V=Z^*,\gamma^*$ using the method of differential equations. Our result provides a prototype to study…

High Energy Physics - Phenomenology · Physics 2019-10-23 Yuxuan Wang , Xiaofeng Xu , Li Lin Yang

Recently presented explicit formulae for asymptotic expansions of Feynman diagrams in the Sudakov limit are applied to typical two-loop diagrams. For a diagram with one non-zero mass these formulae provide an algorithm for analytical…

High Energy Physics - Phenomenology · Physics 2009-10-30 V. A. Smirnov

Calculation of amplitudes in perturbative quantum field theory involve large loop integrals. The complexity of those integrals, in combination with the large number of Feynman diagrams, make the calculations very difficult. Reduction…

High Energy Physics - Phenomenology · Physics 2015-06-05 Ronald H. P. Kleiss , Ioannis Malamos , Costas G. Papadopoulos , Rob Verheyen

We present a method for the integrand-level reduction of two-loop helicity amplitudes in both $d=4-2\epsilon$ and $d=4$ dimensions. The amplitude is expressed in terms of a set of Feynman integrals and their coefficients that depend on the…

High Energy Physics - Phenomenology · Physics 2025-11-14 Giuseppe Bevilacqua , Dhimiter Canko , Costas Papadopoulos , Aris Spourdalakis

A scheme for systematically achieving accurate numerical evaluation of multi-loop Feynman diagrams is developed. This shows the feasibility of a project aimed to produce a complete calculation for two-loop predictions in the Standard Model.…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Passarino

A brief review of recent results on asymptotic expansions of Feynman integrals on the mass shell in momenta and masses and their application to 2-loop calculations is presented.

High Energy Physics - Phenomenology · Physics 2009-10-30 V. A. Smirnov

All one-massless-loop Feynman diagrams could be written like a linear combination of scalar boxes, triangles an bubbles in $n$ dimensions plus rational terms. However, the four-point scalar integrals in $n+2$ dimensions are free of infrared…

High Energy Physics - Phenomenology · Physics 2009-03-11 C Bernicot

We elaborate on the method of differential equations for evaluating Feynman integrals. We focus on systems of equations for master integrals having a linear dependence on the dimensional parameter. For these systems we identify the criteria…

High Energy Physics - Phenomenology · Physics 2015-06-18 Mario Argeri , Stefano Di Vita , Pierpaolo Mastrolia , Edoardo Mirabella , Johannes Schlenk , Ulrich Schubert , Lorenzo Tancredi

In a recent paper \cite{ft} a new powerful method to calculate Feynman diagrams was proposed. It consists in setting up a Taylor series expansion in the external momenta squared. The Taylor coefficients are obtained from the original…

High Energy Physics - Phenomenology · Physics 2016-09-01 J. Fleischer , O. V. Tarasov

We present an integral representation for the parity-even part of the two-loop six-point planar NMHV amplitude in terms of Feynman integrals which have simple transformation properties under the dual conformal symmetry. We probe the dual…

High Energy Physics - Theory · Physics 2011-03-22 D. A. Kosower , R. Roiban , C. Vergu

We compute the symbol of the first two-loop amplitudes in planar ${\cal N}=4$ SYM with algebraic letters, the eight-point NMHV amplitude (or the dual octagon Wilson loops). We show how to apply $\bar{Q}$ equations for computing the…

High Energy Physics - Theory · Physics 2020-03-25 Chi Zhang , Zhenjie Li , Song He

Recently in arXiv:2012.05599 Rudenko presented a formula for the volume of hyperbolic orthoschemes in terms of alternating polylogarithms. We use this result to provide an explicit analytic result for the one-loop scalar n-gon Feynman…

High Energy Physics - Theory · Physics 2024-04-15 Lecheng Ren , Marcus Spradlin , Cristian Vergu , Anastasia Volovich

We compute the leading-color (planar) three-loop four-point amplitude of N=4 supersymmetric Yang-Mills theory in 4 - 2 epsilon dimensions, as a Laurent expansion about epsilon = 0 including the finite terms. The amplitude was constructed…

High Energy Physics - Theory · Physics 2008-11-26 Zvi Bern , Lance J. Dixon , Vladimir A. Smirnov

We compute the two-loop result for the null pentagonal Wilson loop with a Lagrangian insertion (normalized by the Wilson loop without insertion) in planar, maximally supersymmetric Yang-Mills theory. This finite observable is closely…

High Energy Physics - Theory · Physics 2022-04-04 Dmitry Chicherin , Johannes Henn

We compute a complete set of the two-loop Feynman integrals that are required for the next-to-next-to-leading order QCD corrections to on-shell top-pair production in association with a $W$ boson at hadron colliders in the leading colour…

High Energy Physics - Phenomenology · Physics 2025-08-26 Matteo Becchetti , Dhimiter Canko , Vsevolod Chestnov , Tiziano Peraro , Mattia Pozzoli , Simone Zoia

We present a determination of a new class of Feynman diagrams relevant for second-order QCD corrections to the top quark decay t -> b W. Modern computing techniques allow us to perform a reduction of the original loop integrals to master…

High Energy Physics - Phenomenology · Physics 2017-08-23 Maciej Slusarczyk