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Related papers: Four-Point One-Loop Amplitude Computation in the P…

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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 present the complete four-loop four-point amplitude in N=4 super-Yang-Mills theory, for a general gauge group and general D-dimensional covariant kinematics, and including all non-planar contributions. We use the method of maximal cuts…

High Energy Physics - Theory · Physics 2011-03-03 Z. Bern , J. J. M. Carrasco , L. J. Dixon , H. Johansson , R. Roiban

This article is the second of a series of three presenting an alternative method to compute the one-loop scalar integrals. It extends the results of the first article to general complex masses. Let us remind the main features enjoyed by…

High Energy Physics - Theory · Physics 2020-02-26 J. Ph. Guillet , E. Pilon , Y. Shimizu , M. S. Zidi

We present an analytic reconstruction of one-loop amplitudes for the process $0 \to \bar{q}qt\bar{t}H$. Our calculation is a novel use of analytic reconstruction, retaining explicit covariance in the massive spin states through the massive…

High Energy Physics - Phenomenology · Physics 2025-07-28 John M. Campbell , Giuseppe De Laurentis , R. Keith Ellis

We provide high-energy approximations for all one-loop scalar 3- and 4-point functions and the corresponding tensor integrals that appear in scattering processes with four external on-shell particles. Our expressions are valid if all…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Roth , A. Denner

A general formalism for computing only the rational parts of oneloop QCD amplitudes is developed. Starting from the Feynman integral representation of the one-loop amplitude, we use tensor reduction and recursive relations to compute the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Zhi-Guang Xiao , Gang Yang , Chuan-Jie Zhu

We compute explicitly the four-particle amplitude in superstring theories by using the hyperelliptic language and the newly obtained chiral measure of D'Hoker and Phong. Although the algebra of the intermediate steps is a little bit…

High Energy Physics - Theory · Physics 2010-04-05 Zhu-Jun Zheng , Jun-Bao Wu , Chuan-Jie Zhu

We show, for previously uncalculated examples containing a uniform mass in the loop, that it is possible to obtain complete massive one-loop gauge theory amplitudes solely from unitarity and known ultraviolet or infrared mass singularities.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Z. Bern , A. G. Morgan

A FORM program which is used to efficiently expand in components pure spinor superfield expressions of kinematic factors is presented and comments on how it works are made. It is highly customizable using the standard features of FORM and…

High Energy Physics - Theory · Physics 2010-07-29 Carlos R. Mafra

The collinear factorization properties of two-loop scattering amplitudes in dimensionally-regulated N=4 super-Yang-Mills theory suggest that, in the planar ('t Hooft) limit, higher-loop contributions can be expressed entirely in terms of…

High Energy Physics - Theory · Physics 2010-11-15 C. Anastasiou , Z. Bern , L. Dixon , D. A. Kosower

We evaluate one-loop open-string amplitudes at finite $\alpha'$ for the first time. Our method involves a deformation of the integration contour over the modular parameter $\tau$ to a fractal contour introduced by Rademacher in the context…

High Energy Physics - Theory · Physics 2023-09-27 Lorenz Eberhardt , Sebastian Mizera

We present the publicly available program NGluon allowing the numerical evaluation of primitive amplitudes at one-loop order in massless QCD. The program allows the computation of one-loop amplitudes for an arbitrary number of gluons. The…

High Energy Physics - Phenomenology · Physics 2012-08-02 Simon Badger , Benedikt Biedermann , Peter Uwer

We explicitly compute the complete three-loop (O(g^4)) contribution to the four-point function of chiral primary current-like operators <(q)^2 q^2 (q)^2 q^2> in any finite N=2 SYM theory. The computation uses N=2 harmonic supergraphs in…

High Energy Physics - Theory · Physics 2009-10-31 B. Eden , C. Schubert , E. Sokatchev

We show that the one-loop on-shell four-point scattering amplitude of massless $\phi^4$ scalar field theory in 4D Minkowski space time, when Mellin transformed to the Celestial sphere at infinity, transforms covariantly under the global…

High Energy Physics - Theory · Physics 2018-05-09 Nabamita Banerjee , Shamik Banerjee , Sayali Atul Bhatkar , Sachin Jain

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

The spinor-helicity formalism has become an invaluable tool for understanding the S-matrix of massless particles in four dimensions. In this paper we construct a spinor-helicity formalism in six dimensions, and apply it to derive compact…

High Energy Physics - Theory · Physics 2009-07-24 Clifford Cheung , Donal O'Connell

We present a completely numerical method of calculating one-loop amplitudes. Our approach is built upon two different existing methods: the contour deformation and the extrapolation methods. Taking the best features of each of them, we…

High Energy Physics - Phenomenology · Physics 2017-02-01 Goran Duplancic , Bruno Klajn

We find explicit expression for the one-loop four-graviton amplitude in eleven-dimensional supergravity compactified on a circle. Represented in terms of the string coupling (related to the compactification radius) it takes the form of an…

High Energy Physics - Theory · Physics 2009-09-17 J. Russo , A. A. Tseytlin

We recently presented a new method for the evaluation of one-loop amplitude of arbitrary scattering processes, in which the reduction to scalar integrals is performed at the integrand level. In this talk, we review the main features of the…

High Energy Physics - Phenomenology · Physics 2007-09-17 Giovanni Ossola

We define a new geometry obtained from the all-loop amplituhedron in ${\cal N}=4$ SYM by reducing its four-dimensional external and loop momenta to three dimensions. Focusing on the simplest four-point case, we provide strong evidence that…

High Energy Physics - Theory · Physics 2023-01-19 Song He , Chia-Kai Kuo , Zhenjie Li , Yao-Qi Zhang
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