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Related papers: Glue-and-Cut at Five Loops

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We present a method for the direct extraction of rational contributions to one-loop scattering amplitudes, missed by standard four-dimensional unitarity techniques. We use generalised unitarity in $D=4-2\e$ dimensions to write the loop…

High Energy Physics - Phenomenology · Physics 2009-01-27 S. D. Badger

After reduction techniques, two-loop amplitudes in N=4 super Yang-Mills theory can be written in a basis of integrals containing scalar double-box integrals with rational coefficients, though the complete basis is unknown. Generically, at…

High Energy Physics - Theory · Physics 2009-11-11 Evgeny I. Buchbinder , Freddy Cachazo

Extending an argument of [Baikov:2010hf] for the case of 5-loop massless propagators we prove a host of new exact model-independent relations between contributions proportional to odd and even zetas in generic \MSbar\ anomalous dimensions…

High Energy Physics - Phenomenology · Physics 2018-08-01 P. A. Baikov , K. G. Chetyrkin

A general one-loop scattering amplitude may be expanded in terms of master integrals. The coefficients of the master integrals can be obtained from tree-level input in a two-step process. First, use known formulas to write the coefficients…

High Energy Physics - Phenomenology · Physics 2009-01-14 Ruth Britto , Bo Feng , Gang Yang

We present a new method for the momentum expansion of Feynman integrals with arbitrary masses and any number of loops and external momenta. By using the parametric representation we derive a generating function for the coefficients of the…

High Energy Physics - Phenomenology · Physics 2009-10-28 O. V. Tarasov

The \sqrt\epsilon-expansions for critical exponents of the weakly-disordered Ising model are calculated up to the five-loop order and found to possess coefficients with irregular signs and values. The estimate n_c = 2.855 for the marginal…

Statistical Mechanics · Physics 2009-10-31 B. N. Shalaev , S. A. Antonenko , A. I. Sokolov

We calculate the four-loop massless QCD corrections with three closed quark lines to quark and gluon form factors. We apply a novel integration by parts algorithm based on modular arithmetic and compute all relevant master integrals for…

High Energy Physics - Phenomenology · Physics 2017-03-01 Andreas von Manteuffel , Robert M. Schabinger

We present a method for the computation of hepta-cuts of two loop scattering amplitudes. Four dimensional unitarity cuts are used to factorise the integrand onto the product of six tree-level amplitudes evaluated at complex momentum values.…

High Energy Physics - Phenomenology · Physics 2012-04-18 Simon Badger , Hjalte Frellesvig , Yang Zhang

An exact expression for the master integral I_2 arising in three-loop on-shell HQET propagator diagrams with mass is derived and its analytical expansion in the dimensional regularization parameter epsilon is given.

High Energy Physics - Phenomenology · Physics 2008-11-26 A. G. Grozin , T. Huber , D. Maitre

In this work, we compute one-loop planar five-point functions in $\mathcal{N}$=4 super-Yang-Mills using integrability. As in the previous work, we decompose the correlation functions into hexagon form factors and glue them using the weight…

High Energy Physics - Theory · Physics 2018-04-04 Thiago Fleury , Shota Komatsu

We propose a first implementation of the integrand-reduction method for two-loop scattering amplitudes. We show that the residues of the amplitudes on multi-particle cuts are polynomials in the irreducible scalar products involving the loop…

High Energy Physics - Phenomenology · Physics 2015-05-30 Pierpaolo Mastrolia , Giovanni Ossola

We apply a recently suggested new strategy to solve differential equations for master integrals for families of Feynman integrals. After a set of master integrals has been found using the integration-by-parts method, the crucial point of…

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

We present formulas for the coefficients of 2-, 3-, 4- and 5-point master integrals for one-loop massive amplitudes. The coefficients are derived from unitarity cuts in D dimensions. The input parameters can be read off from any…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ruth Britto , Bo Feng , Pierpaolo Mastrolia

We study the three-loop four-point amplitude in ABJM theory. We determine the dual conformal invariant integrals with highest number of propagators and fix their coefficients by two-particle cuts. Evaluating such a combination of integrals…

High Energy Physics - Theory · Physics 2015-06-19 Marco S. Bianchi , Matias Leoni

In this letter we continue the calculation of master integrals for massless three-loop form factors by giving analytical results for those integrals which are relevant for the fermionic contributions proportional to N_F^2, N_F*N, and N_F/N.…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Heinrich , T. Huber , D. Maitre

A method for the evaluation of the epsilon expansion of multi-loop massless Feynman integrals is introduced. This method is based on the Gegenbauer polynomial technique and the expansion of the Gamma function in terms of harmonic sums.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Bekavac

In the first part of this paper, we extend the d-dimensional unitarity cut method of hep-ph/0609191 to cases with massive propagators. We present formulas for integral reduction with which one can obtain coefficients of all pentagon, box,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ruth Britto , Bo Feng

Building upon the algebraic consistency construction of one-loop Bern-Carrasco-Johansson (BCJ) numerators for Yang-Mills (YM) and Yang-Mills-scalar (YMS) theories, we explore the expansion formula of one-loop Einstein-Yang-Mills (EYM)…

High Energy Physics - Theory · Physics 2025-12-23 Yi-Jian Du , Chongsi Xie

We have calculated the five-loop RG expansions of the $n$-component A model of critical dynamics in dimensions $d=4-\varepsilon$ within the Minimal Subtraction scheme. This is made possible by using the advanced diagram reduction method and…

Statistical Mechanics · Physics 2022-06-08 L. Ts. Adzhemyan , D. A. Evdokimov , M. Hnatič , E. V. Ivanova , M. V. Kompaniets , A. Kudlis , D. V. Zakharov

We compute the integrand of the full-colour, two-loop, five-gluon scattering amplitude in pure Yang-Mills theory with all helicities positive, using generalized unitarity cuts. Tree-level BCJ relations, satisfied by amplitudes appearing in…

High Energy Physics - Phenomenology · Physics 2015-10-16 Simon Badger , Gustav Mogull , Alexander Ochirov , Donal O'Connell