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

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We recompute the functions describing the collinear factorization of one-loop amplitudes using the unitarity-based method. We present the results in a form suitable for use as an ingredient in two-loop calculations. We also present a…

High Energy Physics - Phenomenology · Physics 2008-11-26 David A. Kosower , Peter Uwer

We present the one-loop QCD amplitudes for two external massless quarks and three external gluons ($\bar{q}qggg$). This completes the set of one-loop amplitudes needed for the next-to-leading-order corrections to three-jet production at…

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

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

Here we construct N=4 SuperYang-Mills 6 point NMHV loop amplitude (amplitudes with three minus helicities) as a full superspace form, using the $SU(4)_{R}$ anti-commuting spinor variables. Amplitudes with different external particle and…

High Energy Physics - Theory · Physics 2009-11-11 Yu-tin Huang

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

In four-dimensional theories with massless particles, the one-loop amplitudes can be expressed in terms of a basis of scalar integrals and rational terms. Since the scalar bubble integrals are the only UV divergent integrals, the sum of the…

High Energy Physics - Theory · Physics 2015-03-20 Yu-tin Huang , David A. McGady , Cheng Peng

We consider generalization of the Cachazo-Svrcek-Witten (CSW) rules to one-loop amplitudes of N=4 super Yang-Mills theory in a recently developed holonomy formalism in twistor space. We first reconsider off-shell continuation of the…

High Energy Physics - Theory · Physics 2015-05-28 Yasuhiro Abe

We present results for the six-gluon scattering amplitude at one-loop. Since our method is semi-numerical, it yields the result for arbitrary momenta and helicities of the external gluons. We evaluate the colour-ordered sub-amplitudes with…

High Energy Physics - Phenomenology · Physics 2009-11-11 R. K. Ellis , W. T. Giele , Giulia Zanderighi

Prompted by recent progress in the study of N=4 super Yang-Mills amplitudes, and evidence that similar approaches might be relevant to N=8 supergravity, we investigate possible iterative structures and applications of Wilson loop techniques…

High Energy Physics - Theory · Physics 2008-11-26 Andreas Brandhuber , Paul Heslop , Adele Nasti , Bill Spence , Gabriele Travaglini

An efficient numerical algorithm to evaluate one-loop amplitudes using tensor integrals is presented. In particular, it is shown by explicit calculations that for ordered QCD amplitudes with a number of external legs up to 10, its…

High Energy Physics - Phenomenology · Physics 2009-08-11 A. van Hameren

We present new and explicit formulae for the one-loop integrands of scattering amplitudes in non-supersymmetric gauge theory and gravity, valid for any number of particles. The results exhibit the colour-kinematics duality in gauge theory…

High Energy Physics - Theory · Physics 2018-04-04 Yvonne Geyer , Ricardo Monteiro

We review techniques simplifying the analytic calculation of one-loop QCD amplitudes with many external legs, for use in next-to-leading-order corrections to multi-jet processes. Particularly useful are the constraints imposed by…

High Energy Physics - Phenomenology · Physics 2016-09-01 Z. Bern , G. Chalmers , L. Dixon , D. C. Dunbar , D. A. Kosower

We investigate generic properties of one-loop amplitudes in unordered gauge theories in four dimensions. For such theories the organisation of amplitudes in manifestly crossing symmetric expressions poses restrictions on their structure and…

High Energy Physics - Theory · Physics 2012-05-03 Simon Badger , N. E. J. Bjerrum-Bohr , Pierre Vanhove

By exploiting relations between gravity and gauge theories, we present two infinite sequences of one-loop n-graviton scattering amplitudes: the `maximally helicity-violating' amplitudes in N=8 supergravity, and the `all-plus' helicity…

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

Using four-dimensional unitarity and MHV-rules we calculate the one-loop MHV amplitudes with all external particles in the adjoint representation for N=2 supersymmetric QCD with N_f fundamental flavours. We start by considering such…

High Energy Physics - Theory · Physics 2014-11-18 E. W. Nigel Glover , Valentin V. Khoze , Ciaran Williams

We present the two-loop amplitudes for a self-dual Higgs boson with up to four positive helicity gluons in the heavy top-quark limit. Because the tree amplitudes in the all-plus sector vanish, we can construct simple representations of the…

High Energy Physics - Phenomenology · Physics 2026-05-15 Simon Badger , Christian Biello , Colomba Brancaccio , Federico Ripani

The unitarity method for calculating one-loop amplitudes provides algorithms of polynomial complexity. This is primarily beneficial for the computation of multi-leg one loop amplitudes and it is therefore of great interest to develop a…

High Energy Physics - Phenomenology · Physics 2009-04-14 R. Keith Ellis , Walter T. Giele , Zoltan Kunszt

We present work on two-loop amplitudes in pure Yang-Mills theory with all gluons of identical helicity. We show how to obtain their rational terms -- the hardest parts to compute -- via well-understood one-loop unitarity techniques.

High Energy Physics - Phenomenology · Physics 2022-08-15 David A. Kosower , Sebastian Pögel

We extend the twistor string theory inspired formalism introduced in hep-th/0407214 for calculating loop amplitudes in N=4 super Yang-Mills theory to the case of N=1 (and N=2) super Yang-Mills. Our approach yields a novel representation of…

High Energy Physics - Theory · Physics 2011-05-05 James Bedford , Andreas Brandhuber , Bill Spence , Gabriele Travaglini

We derive compact analytical formulae for all tree-level color-ordered gauge theory amplitudes involving any number of external gluons and up to three massless quark-anti-quark pairs. A general formula is presented based on the…

High Energy Physics - Phenomenology · Physics 2011-01-24 Lance J. Dixon , Johannes M. Henn , Jan Plefka , Theodor Schuster
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