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Related papers: Automatic Loop Calculations with FeynArts, FormCal…

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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

A numerical program is presented which facilitates a computation pertaining to the full set of one-gluon loop diagrams (including ghost loop contributions), with M attached external gluon lines in all possible ways. The feasibility of such…

High Energy Physics - Theory · Physics 2009-11-11 A. S. Kapoyannis , A. I. Karanikas , C. N. Ktorides

We discuss the program EXP used to automate the successive application of asymptotic expansions to Feynman diagrams. We focus on the generation of the relevant subgraphs and the determination of the topologies for the remaining integrals.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Th. Seidensticker

We describe the implementation of the MSSM in the diagram generator FeynArts and the calculational tool FormCalc. This extension allows to perform loop calculations of MSSM processes almost fully automatically. The actual implementation has…

High Energy Physics - Phenomenology · Physics 2009-11-07 T. Hahn , C. Schappacher

The method for functional reduction of Feynman integrals, proposed by the author, is used to calculate one-loop integrals corresponding to diagrams with four external lines. The integrals that emerge from amplitudes for the scattering of…

High Energy Physics - Phenomenology · Physics 2023-07-12 O. V. Tarasov

A method of Feynman diagrams summation, based on using Schwinger-Dyson equations and Ward identities, is verified by calculating some four-loop diagrams in N=1 supersymmetric electrodynamics, regularized by higher derivatives. In…

High Energy Physics - Theory · Physics 2009-11-11 A. B. Pimenov , K. V. Stepanyantz

We calculate convergent 3-loop Feynman diagrams containing a single massive loop equipped with twist $\tau =2$ local operator insertions corresponding to spin $N$. They contribute to the massive operator matrix elements in QCD describing…

High Energy Physics - Phenomenology · Physics 2015-06-19 Jakob Ablinger , Johannes Blümlein , Clemens Raab , Carsten Schneider , Fabian Wißbrock

Among 12672 Feynman diagrams contributing to the electron anomalous magnetic moment at the tenth order, 6354 are the diagrams having no lepton loops, i.e., those of quenched type. Because the renormalization structure of these diagrams is…

High Energy Physics - Phenomenology · Physics 2009-11-11 T. Aoyama , M. Hayakawa , T. Kinoshita , M. Nio

New algebraic approach to analytical calculations of D-dimensional integrals for multi-loop Feynman diagrams is proposed. We show that the known analytical methods of evaluation of multi-loop Feynman integrals, such as integration by parts…

High Energy Physics - Theory · Physics 2010-04-05 A. P. Isaev

We describe in some detail the present features of an automatic loop calculation program as well as the integration techniques that go into it. The program, called XLOOPS 1.0, allows one to calculate massive one- and two-loop Feynman…

High Energy Physics - Phenomenology · Physics 2009-09-25 A. Frink , J. G. Körner , J. B. Tausk

An efficient way to calculate one-loop counterterms within the Feynman diagrammatic approach and dimensional regularization is to expand the propagators in the integrands of the Feynman integrals around vanishing external momentum. In this…

High Energy Physics - Phenomenology · Physics 2019-09-04 Christian F. Steinwachs

The calculation of hard scattering amplitudes up to NLO is automated in numerical tools, such as OpenLoops. The LHC and future experiments, however, demand high-precision predictions at NNLO and beyond for a wide range of particle…

High Energy Physics - Phenomenology · Physics 2024-12-20 Natalie Schär , Max F. Zoller

I describe a method to calculate a class of three-loop selfenergy diagrams for arbitrary internal masses and external momentum. This method combines analytical results and numerical integration, and is suitable for implementation in a…

High Energy Physics - Phenomenology · Physics 2009-10-28 Adrian Ghinculov

In this paper, we propose a new method for evaluating scalar one-loop Feynman integrals in generalized D-dimension. The calculations play an important building block for two-loop and higher-loop corrections to the processes at future…

High Energy Physics - Phenomenology · Physics 2017-07-10 Khiem Hong Phan

FeynGame is an open-source software tool to draw Feynman diagrams, but also to get acquainted with their structure. This article reports on a number of new features which have been added to FeynGame since its first release. These include…

High Energy Physics - Phenomenology · Physics 2024-01-24 Robert Harlander , Sven Yannick Klein , Magnus Schaaf

We study a recently-proposed approach to the numerical evaluation of multi-loop Feynman integrals using available sector decomposition programs. As our main example, we consider the two-loop integrals for the $\alpha \alpha_s$ corrections…

High Energy Physics - Phenomenology · Physics 2017-11-08 Andreas von Manteuffel , Robert M. Schabinger

We describe the FeynEdit tool for drawing Feynman diagrams. Input and output is done using the LaTeX macros of FeynArts, which also implies that diagrams drawn by FeynArts can be edited with FeynEdit. The LaTeX code can be conveniently…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. Hahn , P. Lang

A C-program DIANA (DIagram ANAlyser) for the automatic Feynman diagram evaluation is presented. It consists of two parts: the analyzer of diagrams and the interpreter of a special text manipulating language. This language is used to create…

High Energy Physics - Phenomenology · Physics 2011-01-25 M. Tentyukov , J. Fleischer

For the calculation of multi-loop Feynman integrals, a novel numerical method, the Direct Computation Method (DCM) is developed. It is a combination of a numerical integration and a series extrapolation. In principle, DCM can handle…

High Energy Physics - Phenomenology · Physics 2012-01-31 K. Kato , E. de Doncker , N. Hamaguchi , T. Ishikawa , T. Koike , Y. Kurihara , Y. Shimizu , F. Yuasa

FeynRules is a Mathematica-based package which addresses the implementation of particle physics models, which are given in the form of a list of fields, parameters and a Lagrangian, into high-energy physics tools. It calculates the…

High Energy Physics - Phenomenology · Physics 2014-05-30 Adam Alloul , Neil D. Christensen , Celine Degrande , Claude Duhr , Benjamin Fuks