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Related papers: Generalized Unitarity and One-Loop Amplitudes in N…

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We describe the calculation of the one-loop corrections to $H \to \gamma \gamma$ and $g g \to H$ within the four-dimensional unsubtraction/loop-tree duality (FDU/LTD) approach. The fact that these corrections are both IR and UV finite is…

High Energy Physics - Phenomenology · Physics 2017-09-29 German F. R. Sborlini , Felix Driencourt-Mangin , German Rodrigo

We evaluate in great detail one-loop four-graviton field theory amplitudes in pure N=4 D=4 supergravity. The expressions are obtained by taking the field theory limits of (4,0) and (2,2) space-time supersymmetric string theory models. For…

High Energy Physics - Theory · Physics 2013-05-30 Piotr Tourkine , Pierre Vanhove

Two-loop four-gluon N=4 susy amplitudes are evaluated via cutting techniques as a testing ground for QCD. A conjecture for four-point amplitudes to all loop orders is described. We also present a new conjecture for the leading-color part of…

High Energy Physics - Phenomenology · Physics 2009-10-30 Z. Bern , J. Rozowsky , B. Yan

Generalised bi-adjoint scalar amplitudes, obtained from integrations over moduli space of punctured $\mathbb{CP}^{k-1}$, are novel extensions of the CHY formalism. These amplitudes have realisations in terms of Grassmannian cluster…

High Energy Physics - Theory · Physics 2021-05-19 Md. Abhishek , Subramanya Hegde , Arnab Priya Saha

We show how generalised unitarity can be used to determine the one-loop dilatation operator in N=4 super Yang-Mills. Our analysis focuses on two sectors, namely the bosonic SO(6) sector and the SU(2|3) sector. The calculation is performed…

High Energy Physics - Theory · Physics 2015-06-16 Andreas Brandhuber , Brenda Penante , Gabriele Travaglini , Donovan Young

At tree-level, scattering amplitudes involving only gluons or gravitons are unaffected by supersymmetry, allowing them to be efficiently encoded by and extracted from those of maximally supersymmetric (N=4,8) theories. This fails beyond…

High Energy Physics - Theory · Physics 2026-01-01 Jacob L. Bourjaily

We present a new procedure using on-shell recursion to determine coefficients of integral functions appearing in one-loop scattering amplitudes of gauge theories, including QCD. With this procedure, coefficients of integrals, including…

High Energy Physics - Phenomenology · Physics 2009-11-11 Zvi Bern , N. E. J. Bjerrum-Bohr , David C. Dunbar , Harald Ita

We use the duality between color and kinematics to simplify the construction of the complete four-loop four-point amplitude of N=4 super-Yang-Mills theory, including the nonplanar contributions. The duality completely determines the…

High Energy Physics - Theory · Physics 2012-10-17 Z. Bern , J. J. M. Carrasco , L. J. Dixon , H. Johansson , R. Roiban

In this paper we study the scattering amplitudes at strong coupling for the case where the number of gluons is a multiple of four. This is an important missing piece in arXiv:1002.2459. The tricky point for n=4K is that there is some…

High Energy Physics - Theory · Physics 2011-01-27 Gang Yang

We evaluate one-loop amplitudes of N = 4 supergravity in D dimensions using the double-copy procedure that expresses gravity integrands in terms of corresponding ones in Yang--Mills theory.We organize the calculation in terms of a set of…

High Energy Physics - Theory · Physics 2017-11-21 Zvi Bern , Alex Edison , David Kosower , Julio Parra-Martinez

We calculate the one loop amplitudes for the two gluon scattering process in light cone gauge with fermions and scalars circulating in the loop. This extends the earlier works, in which only the gluon circulates the loop. By putting all…

High Energy Physics - Theory · Physics 2008-11-26 J. Qiu

The seven-gluon two-loop full-color Yang-Mills amplitude is presented in a compact analytic form where we use the methods of four-dimensional unitarity cuts to obtain the polylogarithmic pieces and augmented recursion to obtain the rational…

High Energy Physics - Phenomenology · Physics 2025-01-14 Adam R. Dalgleish , David C. Dunbar , Warren B. Perkins , Joseph M. W. Strong

Techniques based upon the string organisation of amplitudes may be used to simplify field theory calculations. We apply these techniques to perturbative gravity and calculate all one-loop amplitudes for four-graviton scattering with…

High Energy Physics - Theory · Physics 2009-10-28 David C. Dunbar , Paul S. Norridge

We present an ansatz for the planar five-loop four-point amplitude in maximally supersymmetric Yang-Mills theory in terms of loop integrals. This ansatz exploits the recently observed correspondence between integrals with simple conformal…

High Energy Physics - Theory · Physics 2008-11-26 Z. Bern , J. J. M. Carrasco , H. Johansson , D. A. Kosower

Unitarity cut method has been proved to be very useful in the computation of one-loop integrals. In this paper, we generalize the method to the situation where the powers of propagators in the denominator are larger than one in general. We…

High Energy Physics - Theory · Physics 2021-08-18 Bo Feng , Hongbin Wang

We present the fully integrated form of the two-loop four-gluon amplitude in $\mathcal{N} = 2$ supersymmetric quantum chromodynamics with gauge group SU$(N_c)$ and with $N_f$ massless supersymmetric quarks (hypermultiplets) in the…

High Energy Physics - Theory · Physics 2019-12-18 Claude Duhr , Henrik Johansson , Gregor Kälin , Gustav Mogull , Bram Verbeek

We present a calculation of the rational terms in two-loop all-plus gluon amplitudes using $D$-dimensional unitarity. We use a conjecture of separability of the two loops, and then a simple generalization of one-loop $D$-dimensional…

High Energy Physics - Phenomenology · Physics 2022-06-30 David A. Kosower , Sebastian Pögel

We report a calculation in N = 4 Yang-Mills of the four-loop term g^4 in the collinear anomalous dimension g(lambda) which governs the universal subleading infrared structure of gluon scattering amplitudes. Using the method of obstructions…

High Energy Physics - Theory · Physics 2008-11-26 Freddy Cachazo , Marcus Spradlin , Anastasia Volovich

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 extend the notion of generalized unitarity cuts to accommodate loop integrals with higher powers of propagators. Such integrals frequently arise in for example integration-by-parts identities, Schwinger parametrizations and Mellin-Barnes…

High Energy Physics - Theory · Physics 2016-12-30 Mads Sogaard , Yang Zhang