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The system of 4 differential equations in the external invariant satisfied by the 4 master integrals of the general massive 2-loop sunrise self-mass diagram is solved by the Runge-Kutta method in the complex plane. The method offers a…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Caffo , H. Czyz , E. Remiddi

We present the powerful module-intersection integration-by-parts (IBP) method, suitable for multi-loop and multi-scale Feynman integral reduction. Utilizing modern computational algebraic geometry techniques, this new method successfully…

High Energy Physics - Theory · Physics 2018-09-11 Janko Boehm , Alessandro Georgoudis , Kasper J. Larsen , Hans Schoenemann , Yang Zhang

We present an efficient algorithm for calculating multiloop Feynman integrals perturbatively.

Quantum Physics · Physics 2009-10-31 Boris Kastening , Hagen Kleinert

In this article, we explore the use of contour deformation for the numerical evaluation of Feynman integrals after sector decomposition. In existing codes, the contour of integration is determined heuristically for each phase-space point by…

High Energy Physics - Phenomenology · Physics 2026-02-16 Stephen Jones , Daniel Maître , Anton Olsson

As the new-generation precision experiments such as MOLLER and P2 look for physics beyond Standard Model, it is becoming increasingly important to evaluate the higher-order electroweak radiative corrections to a sub-percent level of…

High Energy Physics - Theory · Physics 2019-12-11 A. Aleksejevs , S. Barkanova

We propose a new approach that allows for the separate numerical calculation of the real and imaginary parts of finite loop integrals. We find that at one-loop the real part is given by the Loop-Tree Duality integral supplemented with…

High Energy Physics - Phenomenology · Physics 2022-02-01 Dario Kermanschah

A comprehensive study is performed of general massive, scalar, two-loop Feynman diagrams with three external legs. Algorithms for their numerical evaluation are introduced and discussed, numerical results are shown for all different…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Ferroglia , G. Passarino , M. Passera , S. Uccirati

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

A recently introduced approach to the classical gravitational dynamics of binary systems involves intricate integrals (linked to a combination of nonlocal-in-time interactions with iterated $\frac1r$-potential scattering) which have so far…

General Relativity and Quantum Cosmology · Physics 2021-02-24 Donato Bini , Thibault Damour , Andrea Geralico , Stefano Laporta , Pierpaolo Mastrolia

Local, manifestly dual-conformally invariant loop integrands are now known for all finite quantities associated with observables in planar, maximally supersymmetric Yang-Mills theory through three loops. These representations, however, are…

High Energy Physics - Theory · Physics 2019-05-01 Jacob L. Bourjaily , Falko Dulat , Erik Panzer

We present a new method for the numerical evaluation of arbitrary loop integrals in dimensional regularization. We first derive Mellin-Barnes integral representations and apply an algorithmic technique, based on the Cauchy theorem, to…

High Energy Physics - Phenomenology · Physics 2009-11-11 Charalampos Anastasiou , Alejandro Daleo

This is a status report of the evaluation of the three-loop corrections to the static QCD potential of a heavy quark and an antiquark. The families of Feynman integrals that appear in the evaluation are described. To reduce any integral of…

High Energy Physics - Phenomenology · Physics 2015-05-13 Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We analytically evaluate the three-loop Feynman integral which was the last missing ingredient for the analytical evaluation of the three-loop quark static potential. To evaluate the integral we introduce an auxiliary parameter $y$, which…

High Energy Physics - Phenomenology · Physics 2016-11-23 Roman N. Lee , Vladimir A. Smirnov

We elucidate the vector space (twisted relative cohomology) that is Poincar\'e dual to the vector space of Feynman integrals (twisted cohomology) in general spacetime dimension. The pairing between these spaces - an algebraic invariant…

High Energy Physics - Theory · Physics 2022-01-05 Simon Caron-Huot , Andrzej Pokraka

We reformulate differential equations (DEs) for Feynman integrals to avoid doubled propagators in intermediate steps. External momentum derivatives are dressed with loop momentum derivatives to form tangent vectors to unitarity cut…

High Energy Physics - Theory · Physics 2017-06-26 Mao Zeng

We evaluate analytically the master integrals for one of two types of planar families contributing to massive two-loop Bhabha scattering in QED. As in our previous paper, we apply a recently suggested new strategy to solve differential…

High Energy Physics - Theory · Physics 2015-06-16 Johannes M. Henn , Vladimir A. Smirnov

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

We review in a pedagogical way the method of differential equations for the evaluation of D-dimensionally regulated Feynman integrals. After dealing with the general features of the technique, we discuss its application in the context of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mario Argeri , Pierpaolo Mastrolia

The calculation of higher-order corrections in Quantum Field Theories is a challenging task. In particular, dealing with multiloop and multileg Feynman amplitudes leads to severe bottlenecks and a very fast scaling of the computational…

High Energy Physics - Phenomenology · Physics 2023-05-16 German F. R. Sborlini

The 4-th order Runge-Kutta method in the complex plane is proposed for numerically advancing the solutions of a system of first order differential equations in one external invariant satisfied by the master integrals related to a Feynman…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Caffo , H. Czyz , E. Remiddi