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We calculate one-loop scattering amplitudes in N=4 super Yang-Mills theory away from the origin of the moduli space and demonstrate that the results are extremely simple, in much the same way as in the conformally invariant theory.…

High Energy Physics - Theory · Physics 2015-02-23 Robert M. Schabinger

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

We argue that generic one-loop scattering amplitudes in supersymmetric Yang-Mills theories can be computed equivalently with MHV diagrams or with Feynman diagrams. We first present a general proof of the covariance of one-loop non-MHV…

High Energy Physics - Theory · Physics 2009-11-11 Andreas Brandhuber , Bill Spence , Gabriele Travaglini

We study our Schwinger-Dyson equation as well as the large $N_{c}$ loop equation for supersymmetric Yang-Mills theory in four dimensions by the N=1 superspace Wilson-loop variable. We are successful in deriving a new manifestly…

High Energy Physics - Theory · Physics 2009-10-30 Hiroshi Itoyama , Hiroyuki Takashino

We use 4d ambitwistor string theory to derive new worldsheet formulae for tree-level conformal supergravity amplitudes supported on refined scattering equations. Unlike the worldsheet formulae for super-Yang-Mills or supergravity, the…

High Energy Physics - Theory · Physics 2018-07-12 Joseph A. Farrow , Arthur E. Lipstein

We review current efficient techniques for the construction of multi-leg and multi-loop on-shell scattering amplitudes in supersymmetric gauge theories. Examples in the maximally supersymmetric Yang-Mills theory in four dimensions are…

High Energy Physics - Theory · Physics 2015-05-20 R. Roiban

We show how the MHV diagram description of Yang-Mills theories can be used to study non-supersymmetric loop amplitudes. In particular, we derive a compact expression for the cut-constructible part of the general one-loop MHV multi-gluon…

High Energy Physics - Theory · Physics 2010-12-14 James Bedford , Andreas Brandhuber , Bill Spence , Gabriele Travaglini

We introduce two new graphical-level relations among possible contributions to the four-point correlation function and scattering amplitude in planar, maximally supersymmetric Yang-Mills theory. When combined with the rung rule, these prove…

High Energy Physics - Theory · Physics 2016-12-21 Jacob L. Bourjaily , Paul Heslop , Vuong-Viet Tran

We show how generalised unitarity cuts in D = 4 - 2 epsilon dimensions can be used to calculate efficiently complete one-loop scattering amplitudes in non-supersymmetric Yang-Mills theory. This approach naturally generates the rational…

High Energy Physics - Theory · Physics 2009-11-11 Andreas Brandhuber , Simon McNamara , Bill Spence , Gabriele Travaglini

We review how (dimensionally regulated) scattering amplitudes in N=4 super-Yang-Mills theory provide a useful testing ground for perturbative QCD calculations relevant to collider physics, as well as another avenue for investigating the…

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

This article reviews recent progress in formulating double-copy constructions for scattering amplitudes in supergravity theories with N=2 supersymmetry in five and four spacetime dimensions. Particular attention is devoted to infinite…

High Energy Physics - Theory · Physics 2016-07-15 Marco Chiodaroli

Scattering amplitudes with spinning particles are shown to decompose into multiple copies of simple building blocks to all loop orders, which can be used to efficiently reduce these amplitudes to sums over scalar integrals. Absence of…

High Energy Physics - Phenomenology · Physics 2018-05-28 Rutger H. Boels , Qingjun Jin , Hui Luo

One-loop scattering amplitudes in N=4 super Yang-Mills (SYM) theories are analyzed in the paradigm of maximal helicity violating Feynman diagrams. There are very limited number of loop integrals to be evaluated. For a process with n…

High Energy Physics - Theory · Physics 2010-04-05 Mingxing Luo , Congkao Wen

Recently it has been argued that tree-level scattering amplitudes in N=4 Yang-Mills theory are uniquely determined by a careful study of their superconformal and Yangian symmetries. However, at one-loop order these symmetries are known to…

High Energy Physics - Theory · Physics 2010-04-22 Niklas Beisert , Johannes Henn , Tristan McLoughlin , Jan Plefka

Scattering amplitudes in $D$ dimensions involve particular terms that originate from the interplay of UV poles with the $D-4$ dimensional parts of loop numerators. Such contributions can be controlled through a finite set of…

High Energy Physics - Phenomenology · Physics 2020-10-28 Jean-Nicolas Lang , Stefano Pozzorini , Hantian Zhang , Max F. Zoller

We present a new formula for all single trace tree amplitudes in four dimensional super Yang-Mills coupled to Einstein supergravity. Like the Cachazo-He-Yuan formula, our expression is supported on solutions of the scattering equations, but…

High Energy Physics - Theory · Physics 2016-01-27 Tim Adamo , Eduardo Casali , Kai A. Roehrig , David Skinner

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 study the effect of loop corrections to conformal correlators on the celestial sphere at null infinity. We first analyze finite one-loop celestial amplitudes in pure Yang-Mills theory and Einstein gravity. We then turn to our main focus:…

High Energy Physics - Theory · Physics 2021-01-04 Hernan A. Gonzalez , Andrea Puhm , Francisco Rojas

In this paper we review recent results on symmetries in N=4 super Yang-Mills theory. Symmetries are of invaluable help in studying and constraining the scattering amplitudes, and there has been a lot of progress in recent years concerning…

High Energy Physics - Theory · Physics 2015-03-19 L. Ferro

We describe new on-shell recursion relations for tree-amplitudes in N=1 and N=2 gauge theories and use these to show that the structure of the S-matrix in pure N=1 and N=2 gauge theories resembles that of pure Yang-Mills. We proceed to…

High Energy Physics - Theory · Physics 2010-05-25 Shailesh Lal , Suvrat Raju