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Related papers: Dissolving N=4 loop amplitudes into QCD tree ampli…

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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

We present a supersymmetric recursion relation for tree-level scattering amplitudes in N=4 super Yang-Mills. Using this recursion relation, we prove that the tree-level S-matrix of the maximally supersymmetric theory is covariant under dual…

High Energy Physics - Theory · Physics 2008-12-30 Andreas Brandhuber , Paul Heslop , Gabriele Travaglini

We study tree level scattering amplitudes of four massless states in the double scaled little string theory, and compare them to perturbative loop amplitudes in six-dimensional super-Yang-Mills theory. The little string amplitudes are…

High Energy Physics - Theory · Physics 2015-06-22 Chi-Ming Chang , Ying-Hsuan Lin , Shu-Heng Shao , Yifan Wang , Xi Yin

We present an algorithm for the numerical calculation of one-loop QCD amplitudes. The algorithm consists of subtraction terms, approximating the soft, collinear and ultraviolet divergences of one-loop amplitudes and a method to deform the…

High Energy Physics - Phenomenology · Physics 2010-12-09 Sebastian Becker , Christian Reuschle , Stefan Weinzierl

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 an explicit expression for a particular $n$-gluon two loop scattering partial amplitude. Specifically we present an analytic form for the single trace $N_c$ independent colour partial amplitude for the case where all external…

High Energy Physics - Phenomenology · Physics 2020-04-08 David C. Dunbar , Warren B. Perkins , Joseph M. W. Strong

We derive a compact expression for the three-point MHV form factors of half-BPS operators in N=4 super Yang-Mills at two loops. The main tools of our calculation are generalised unitarity applied at the form factor level, and the compact…

High Energy Physics - Theory · Physics 2015-06-03 Andreas Brandhuber , Gabriele Travaglini , Gang Yang

We present a method to compute the integrands of one-loop Einstein-Yang-Mills amplitudes for any number of external gauge and gravity multiplets. Our construction relies on the double-copy structure of Einstein-Yang-Mills as…

High Energy Physics - Theory · Physics 2023-03-01 Franziska Porkert , Oliver Schlotterer

Recently it has been proposed that gluon scattering amplitudes in gauge theory can be computed from the D-instanton expansion of the topological B-model on P^{3|4}, although only maximally helicity violating (MHV) amplitudes have so far…

High Energy Physics - Theory · Physics 2009-11-10 Radu Roiban , Marcus Spradlin , Anastasia Volovich

We present all-multiplicity formulae, derived from first principles in the MHV sector and motivated by twistor string theory for general helicities, for the tree-level S-matrix of gluon scattering on self-dual radiative backgrounds. These…

High Energy Physics - Theory · Physics 2023-05-11 Tim Adamo , Lionel Mason , Atul Sharma

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

Recent advances in our understanding of tree-level QCD amplitudes in the massless limit exploiting an effective (maximal) supersymmetry have led to the complete analytic construction of tree-amplitudes with up to four external…

High Energy Physics - Phenomenology · Physics 2013-02-08 Simon Badger , Benedikt Biedermann , Lucas Hackl , Jan Plefka , Theodor Schuster , Peter Uwer

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 describe a new method to perform NLO calculations, combining real and virtual amplitudes at the integrand level, with a fully local compensation between them in the IR, and between the virtual integrand and properly defined counter-terms…

High Energy Physics - Phenomenology · Physics 2016-08-08 German Rodrigo , Felix Driencourt-Mangin , German F. R. Sborlini , Roger Jose Hernandez-Pinto

We report on a technique for evaluating finite unitarity cut for one-loop amplitudes in gauge theories, and discuss its application to the cut-constructible part of six-gluon amplitude in QCD.

High Energy Physics - Phenomenology · Physics 2009-11-11 Pierpaolo Mastrolia

We study cluster adjacency conjectures for amplitudes in maximally supersymmetric Yang-Mills theory. We show that the n-point one-loop NMHV ratio function satisfies Steinmann cluster adjacency. We also show that the one-loop BDS-like…

High Energy Physics - Theory · Physics 2021-02-03 Jorge Mago , Anders Schreiber , Marcus Spradlin , Anastasia Volovich

A central problem in quantum field theory is the computation of scattering amplitudes. However, traditional methods are impractical to calculate high order phenomenologically relevant observables. Building on a few decades of astonishing…

High Energy Physics - Theory · Physics 2017-06-28 Livia Ferro , Tomasz Lukowski , Andrea Orta , Matteo Parisi

We construct all supergravity theories that can be obtained through factorized orbifold projections of N=8 supergravity, exposing their double-copy structure, and calculate their one-loop four-point scattering amplitudes. We observe a…

High Energy Physics - Theory · Physics 2015-06-12 John Joseph M. Carrasco , Marco Chiodaroli , Murat Gunaydin , Radu Roiban

We consider scattering amplitudes in planar N = 4 supersymmetric Yang-Mills theory in special kinematics where all external four-dimensional momenta are restricted to a (1+1)-dimensional subspace. The amplitudes are known to satisfy…

High Energy Physics - Theory · Physics 2015-06-05 Timothy Goddard , Paul Heslop , Valentin V. Khoze

In this work, we express the singular part of a scattering amplitude in terms of Feynman integrals compatible with topologies appearing in the bare amplitude, and we choose a basis of locally finite Master Integrals. In two-loop massless…

High Energy Physics - Phenomenology · Physics 2025-12-18 Piotr Bargiela