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Related papers: Hypergeometric Functions and Feynman Diagrams

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We review the hypergeometric function approach to Feynman diagrams. Special consideration is given to the construction of the Laurent expansion. As an illustration, we describe a collection of physically important one-loop vertex diagrams…

High Energy Physics - Theory · Physics 2008-11-01 M. Yu. Kalmykov , Bernd A. Kniehl , B. F. L. Ward , S. A. Yost

We present a new methodology, suitable for implementation on computer, to perform the $\epsilon$-expansion of hypergeometric functions with linear $\epsilon$ dependent Pochhammer parameters in any number of variables. Our approach allows…

Mathematical Physics · Physics 2023-03-28 Souvik Bera

We continue our study of the construction of analytical coefficients of the epsilon-expansion of hypergeometric functions and their connection with Feynman diagrams. In this paper, we apply the approach of obtaining iteratated solutions to…

High Energy Physics - Theory · Physics 2009-04-03 M. Yu. Kalmykov , B. F. L. Ward , S. A. Yost

Higher-order diagrams required for radiative corrections to mixed electroweak and QCD processes at the LHC and anticipated future colliders will require numerically stable representations of the associated Feynman diagrams. The…

Mathematical Physics · Physics 2011-10-25 S. A. Yost , V. V. Bytev , M. Yu. Kalmykov , B. A. Kniehl , B. F. L. Ward

The Gauss hypergeometric functions 2F1 with arbitrary values of parameters are reduced to two functions with fixed values of parameters, which differ from the original ones by integers. It is shown that in the case of integer and/or…

High Energy Physics - Theory · Physics 2008-11-26 M. Yu. Kalmykov

Hypergeometric functions provide a useful representation of Feynman diagrams occuring in precision phenomenology. In dimension regularization, the epsilon-expansion of these functions about d=4 is required. We discuss the current status of…

High Energy Physics - Phenomenology · Physics 2008-10-06 S. A. Yost , M. Yu. Kalmykov , B. F. L. Ward

The scalar three-point function appearing in one-loop Feynman diagrams is compactly expressed in terms of a generalized hypergeometric function of two variables. Use is made of the connection between such Appell function and dilogarithms…

High Energy Physics - Phenomenology · Physics 2015-06-25 Luis G. Cabral-Rosetti , Miguel A. Sanchis-Lozano

Present and future high-precision tests of the Standard Model and beyond for the fundamental constituents and interactions in Nature are demanding complex perturbative calculations involving multi-leg and multi-loop Feynman diagrams.…

High Energy Physics - Phenomenology · Physics 2011-04-15 Luis G. Cabral-Rosetti , Miguel A. Sanchis-Lozano

When calculating higher terms of the epsilon-expansion of massive Feynman diagrams, one needs to evaluate particular cases of multiple inverse binomial sums. These sums are related to the derivatives of certain hypergeometric functions with…

High Energy Physics - Theory · Physics 2008-11-26 A. I. Davydychev , M. Yu. Kalmykov

For certain dimensionally-regulated one-, two- and three-loop diagrams, problems of constructing the epsilon-expansion and the analytic continuation of the results are studied. In some examples, an arbitrary term of the epsilon-expansion…

High Energy Physics - Theory · Physics 2025-10-20 A. I. Davydychev , M. Yu. Kalmykov

We continue the study of the construction of analytical coefficients of the epsilon-expansion of hypergeometric functions and their connection with Feynman diagrams. In this paper, we show the following results: Theorem A: The multiple…

High Energy Physics - Theory · Physics 2009-11-18 M. Yu. Kalmykov , B. F. L. Ward , S. A. Yost

Application of the geometrically-inspired representations to the epsilon-expansion of the two-point function with different masses is considered. Explicit result for an arbitrary term of the expansion is obtained in terms of log-sine…

High Energy Physics - Theory · Physics 2007-05-23 A. I. Davydychev

Some problems related to the structure of higher terms of the epsilon-expansion of Feynman diagrams are discussed.

High Energy Physics - Theory · Physics 2007-05-23 A. I. Davydychev , M. Yu. Kalmykov

Several new relationships between hypergeometric functions are found by comparing results for Feynman integrals calculated using different methods. A new expression for the one-loop propagator-type integral with arbitrary masses and…

Mathematical Physics · Physics 2015-05-30 Bernd A. Kniehl , Oleg V. Tarasov

An arbitrary term of the epsilon-expansion of dimensionally regulated off-shell massless one-loop three-point Feynman diagram is expressed in terms of log-sine integrals related to the polylogarithms. Using magic connection between these…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. I. Davydychev

In this talk, we discuss the algorithm for the construction of analytical coefficients of higher order epsilon expansion of some Horn type hypergeometric functions of two variables around rational values of parameters.

High Energy Physics - Theory · Physics 2013-01-14 Vladimir V. Bytev , Mikhail Yu. Kalmykov , Bernd A. Kniehl

We will present some (formal) arguments that any Feynman diagram can be understood as a particular case of a Horn-type multivariable hypergeometric function. The advantages and disadvantages of this type of approach to the evaluation of…

High Energy Physics - Theory · Physics 2014-11-18 M. Yu. Kalmykov , V. V. Bytev , Bernd A. Kniehl , B. F. L. Ward , S. A. Yost

Hypergeometric structures in single and multiscale Feynman integrals emerge in a wide class of topologies. Using integration-by-parts relations, associated master or scalar integrals have to be calculated. For this purpose it appears useful…

Mathematical Physics · Physics 2021-12-01 J. Blümlein , M. Saragnese , C. Schneider

New explicit expressions are derived for the one-loop two-point Feynman integral with arbitrary external momentum and masses $m_1^2$ and $m_2^2$ in D dimensions. The results are given in terms of Appell functions, manifestly symmetric with…

High Energy Physics - Theory · Physics 2008-11-26 M. A. Shpot

Hypergeometric function method is proposed to calculate the scalar integrals of Feynman diagrams. For the scalar integral of three-loop vacuum diagram with four-propagator, we verify the equivalency of Feynman parametrization and the…

High Energy Physics - Phenomenology · Physics 2019-09-04 Zhi-Hua Gu , Hai-Bin Zhang
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