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Feynman diagrams are a pictorial way of describing integrals predicting possible outcomes of interactions of subatomic particles in the context of quantum field physics. It is highly desirable to have an intrinsic mathematical…

Representation Theory · Mathematics 2016-11-02 Matvei Libine

We present an algorithm to evaluate multiloop Feynman integrals with an arbitrary number of internal massive lines, with the masses being in general complex-valued, and its implementation in the \textsc{Mathematica} package…

High Energy Physics - Phenomenology · Physics 2022-10-24 Tommaso Armadillo , Roberto Bonciani , Simone Devoto , Narayan Rana , Alessandro Vicini

A method to calculate two-loop self-energy diagrams of the Standard Model is demonstrated. A direct physical application is the calculation of the two-loop electroweak contribution to the anomalous magnetic moment of the muon…

High Energy Physics - Phenomenology · Physics 2011-04-15 L. Avdeev , J. Fleischer , M. Yu. Kalmykov , M. Tentyukov

In theories like SM or MSSM with a complex gauge group structure the complete set of Feynman diagrams contributed to a particular physics process can be splited to exact gauge invariant subsets. Arguments and examples given in the review…

High Energy Physics - Phenomenology · Physics 2009-11-07 E. E. Boos

We describe the unitarity approach for the numerical computation of two-loop integral coefficients of scattering amplitudes. It is well known that the leading propagator singularities of an amplitude's integrand are related to products of…

High Energy Physics - Phenomenology · Physics 2017-06-07 S. Abreu , F. Febres Cordero , H. Ita , M. Jaquier , B. Page

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

The status of analytical evaluation of double and triple box diagrams is characterized. The method of Mellin-Barnes representation as a tool to evaluate master integrals in these problems is advocated. New MB representations for massive…

High Energy Physics - Phenomenology · Physics 2009-11-10 V. A. Smirnov

We give an overview of state-of-the-art multi-loop Feynman diagram computations, and explain how we use symbolic manipulation to generate renormalized integrals that are then evaluated numerically. We explain how we automate BPHZ…

High Energy Physics - Phenomenology · Physics 2007-12-07 A. D. Kennedy , T. Binoth , T. Rippon

We present results on the two-loop leading and angular-dependent next-to-leading logarithmic virtual corrections to arbitrary processes at energies above the electroweak scale. In the `t Hooft-Feynman gauge the relevant Feynman diagrams…

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

We revisit the conjectural method called Schubert analysis for generating the alphabet of symbol letters for Feynman integrals, which was based on geometries of intersecting lines associated with corresponding cut diagrams. We explain the…

High Energy Physics - Theory · Physics 2024-10-16 Song He , Xuhang Jiang , Jiahao Liu , Qinglin Yang

An algorithm for the reduction of one-loop n-point tensor integrals to basic integrals is proposed. We transform tensor integrals to scalar integrals with shifted dimension and reduce these by recurrence relations to integrals in generic…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Fleischer , F. Jegerlehner , O. V. Tarasov

We review recent progress that we have achieved in evaluating the class of fully massive vacuum integrals at five loops. After discussing topics that arise in classification, evaluation and algorithmic codification of this specific set of…

High Energy Physics - Phenomenology · Physics 2016-12-21 Thomas Luthe , York Schroder

We present a method to construct a suitable contour deformation in loop momentum space for multi-loop integrals. This contour deformation can be used to perform the integration for multi-loop integrals numerically. The integration can be…

High Energy Physics - Phenomenology · Physics 2015-06-12 Sebastian Becker , Stefan Weinzierl

Over the last year significant progress was made in the understanding of the computation of Feynman integrals using differential equations. These lectures give a review of these developments, while not assuming any prior knowledge of the…

High Energy Physics - Phenomenology · Physics 2015-06-23 Johannes M. Henn

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 2007-05-23 Michele Caffo

Several powerful techniques for evaluating massless scalar Feynman diagrams are developed, viz: the solution of recurrence relations to evaluate diagrams with arbitrary numbers of loops in $n=4-2\omega$ dimensions; the discovery and use of…

High Energy Physics - Theory · Physics 2016-04-28 David J. Broadhurst

We introduce the tools of intersection theory to the study of Feynman integrals, which allows for a new way of projecting integrals onto a basis. In order to illustrate this technique, we consider the Baikov representation of maximal cuts…

High Energy Physics - Theory · Physics 2019-03-06 Pierpaolo Mastrolia , Sebastian Mizera

We focus on numerical techniques for expanding 3-loop Feynman integrals with respect to the dimensional regularization parameter $\varepsilon,$ which is related to the space-time dimension as $\nu = 4-2\varepsilon,$ and describes underlying…

High Energy Physics - Phenomenology · Physics 2024-08-14 E de Doncker , F Yuasa , T Ishikawa , K Kato

We present the program SecDec 2.0 which contains various new features: First, it allows the numerical evaluation of multi-loop integrals with no restriction on the kinematics. Dimensionally regulated ultraviolet and infrared singularities…

High Energy Physics - Phenomenology · Physics 2015-03-20 Sophia Borowka , Jonathon Carter , Gudrun Heinrich

We introduce a novel compositional description of Feynman diagrams, with well-defined categorical semantics as morphisms in a dagger-compact category. Our chosen setting is suitable for infinite-dimensional diagrammatic reasoning,…

Quantum Physics · Physics 2022-05-03 Razin A. Shaikh , Stefano Gogioso