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Related papers: One-loop four-point amplitudes in pure and matter-…

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We expose a double-copy structure in the scattering amplitudes of the generic Jordan family of N=2 Maxwell-Einstein and Yang-Mills/Einstein supergravity theories in four and five dimensions. The Maxwell-Einstein supergravity amplitudes are…

High Energy Physics - Theory · Physics 2015-06-22 Marco Chiodaroli , Murat Gunaydin , Henrik Johansson , Radu Roiban

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 construct the three-loop four-point amplitude of N=8 supergravity using the unitarity method. The amplitude is ultraviolet finite in four dimensions. Novel cancellations, not predicted by traditional superspace power-counting arguments,…

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

We examine the ultraviolet behaviour of supergravity theories as a function of dimension and number of supercharges. We do so by the computation of one and two-loop physical on-shell four point amplitudes. For maximal supergravity, our…

High Energy Physics - Theory · Physics 2007-05-23 Z. Bern , D. Dunbar , L. Dixon , B. Julia , M. Perelstien , J. Rozowsky , D. Seminara , M. Trigante

We characterise the one-loop amplitudes for N=6 and N=4 supergravity in four dimensions. For N=6 we find that the one-loop n-point amplitudes can be expanded in terms of scalar box and triangle functions only. This simplification is…

High Energy Physics - Theory · Physics 2011-09-22 David C. Dunbar , James H. Ettle , Warren B. Perkins

We investigate Yangian-invariant deformations of one-loop amplitudes in N = 4 super-Yang-Mills theory employing an algebraic representation of amplitudes. In this language, we reproduce the deformed massless box integral describing the…

High Energy Physics - Theory · Physics 2015-06-22 Johannes Broedel , Marius de Leeuw , Matteo Rosso

Using the method of maximal cuts, we construct the complete D-dimensional integrand of the five-loop four-point amplitude of N = 4 super-Yang-Mills theory, including nonplanar contributions. In the critical dimension where this amplitude…

High Energy Physics - Theory · Physics 2015-03-20 Z. Bern , J. J. M. Carrasco , H. Johansson , R. Roiban

In this thesis, we study the all same helicity loop amplitudes in self-dual Yang-Mills and self-dual gravity. These amplitudes have long been conjectured to be interpreted as an anomaly and are recently linked to the UV divergence of…

High Energy Physics - Theory · Physics 2023-10-24 Pratik Chattopadhyay

We use supersymmetric generalised unitarity to calculate supercoefficients of box functions in the expansion of scattering amplitudes in N=8 supergravity at one loop. Recent advances have presented tree-level amplitudes in N=8 supergravity…

High Energy Physics - Theory · Physics 2009-09-28 Panagiotis Katsaroumpas , Bill Spence , Gabriele Travaglini

We use the recently developed generalized double-copy procedure to construct an integrand for the five-loop four-point amplitude of N=8 supergravity. This construction starts from a naive double copy of the previously computed corresponding…

High Energy Physics - Theory · Physics 2017-12-27 Zvi Bern , John Joseph M. Carrasco , Wei-Ming Chen , Henrik Johansson , Radu Roiban , Mao Zeng

The decomposition of a one-loop scattering amplitude into elementary functions with rational coefficients introduces spurious singularities which afflict individual coefficients but cancel in the complete amplitude. These cancellations…

High Energy Physics - Theory · Physics 2013-05-29 David C. Dunbar , James H. Ettle , Warren B. Perkins

Four-point one-loop nonsupersymmetric pure Yang-Mills amplitudes with the duality between color and kinematics manifest have been constructed in previous work. Here, we extend the discussion to fermions and scalars circulating in the loop…

High Energy Physics - Theory · Physics 2015-11-04 Josh Nohle

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

Using the method of maximal cuts, we obtain a form of the three-loop four-point scattering amplitude of N=8 supergravity in which all ultraviolet cancellations are made manifest. The Feynman loop integrals that appear have a graphical…

High Energy Physics - Theory · Physics 2009-11-13 Z. Bern , J. J. M. Carrasco , L. J. Dixon , H. Johansson , R. Roiban

Using cutting techniques we obtain the two-loop N=4 super-Yang-Mills helicity amplitudes for four-gluon scattering in terms of scalar integral functions. The N=4 amplitudes are considerably simpler than corresponding QCD amplitudes and…

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

We compute the leading-color (planar) three-loop four-point amplitude of N=4 supersymmetric Yang-Mills theory in 4 - 2 epsilon dimensions, as a Laurent expansion about epsilon = 0 including the finite terms. The amplitude was constructed…

High Energy Physics - Theory · Physics 2008-11-26 Zvi Bern , Lance J. Dixon , Vladimir A. Smirnov

String theory implies that field theories containing gravity are in a certain sense `products' of gauge theories. We make this product structure explicit up to two loops for the relatively simple case of N=8 supergravity four-point…

High Energy Physics - Theory · Physics 2010-11-15 Z. Bern , L. Dixon , D. C. Dunbar , M. Perelstein , J. S. Rozowsky

Using the double-copy construction of Yang-Mills-Einstein theories formulated in our earlier work, we obtain compact presentations for single-trace Yang-Mills-Einstein tree amplitudes with up to five external gravitons and an arbitrary…

High Energy Physics - Theory · Physics 2017-08-25 Marco Chiodaroli , Murat Gunaydin , Henrik Johansson , Radu Roiban

We find that scattering amplitudes in massive scalar QCD can manifest the duality between color and kinematics at loop-level. Specifically we construct the one-loop integrands for four-point scattering between two distinct massive scalars,…

High Energy Physics - Theory · Physics 2021-02-10 John Joseph M. Carrasco , Ingrid A. Vazquez-Holm

We present an explicit formula for the n-point MHV one-loop amplitude in a N=4 supergravity theory. This formula is derived from the soft and collinear factorisations of the amplitude.

High Energy Physics - Theory · Physics 2015-06-03 David C. Dunbar , James H. Ettle , Warren B. Perkins