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Related papers: On one-loop amplitudes in gauge theories

200 papers

One-loop amplitudes of gluons in supersymmetric Yang-Mills are four-dimensional cut-constructible. This means that they can be determined from their unitarity cuts. We present a new systematic procedure to explicitly carry out any finite…

High Energy Physics - Phenomenology · Physics 2009-07-09 Ruth Britto , Evgeny Buchbinder , Freddy Cachazo , Bo Feng

We identify a large class of one-loop amplitudes for massless particles that can be constructed via unitarity from tree amplitudes, without any ambiguities. One-loop amplitudes for massless supersymmetric gauge theories fall into this…

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

We show that one-loop amplitudes in massless gauge theories can be determined from single cuts. By cutting a single propagator and putting it on-shell, the integrand of an n-point one-loop integral is transformed into an (n+2)-particle tree…

High Energy Physics - Theory · Physics 2008-12-25 E. W. Nigel Glover , Ciaran Williams

We present a technique which utilizes unitarity and collinear limits to construct ansatze for one-loop amplitudes in gauge theory. As an example, we obtain the one-loop contribution to amplitudes for $n$ gluon scattering in $N=4$…

High Energy Physics - Phenomenology · Physics 2009-09-25 Z. Bern , L. Dixon , D. C. Dunbar , D. A. Kosower

In this paper, we give the general expressions for a special series of tree amplitudes of the Yang-Mills theory. This series of amplitudes have two adjacent massless spin-1 particles with extra-dimensional momenta and any number of positive…

High Energy Physics - Theory · Physics 2019-10-08 Yang An , Yi Li

One-loop amplitudes of gluons in N=4 gauge theory can be written as linear combinations of known scalar box integrals with coefficients that are rational functions. In this paper we show how to use generalized unitarity to basically read…

High Energy Physics - Theory · Physics 2009-11-10 Ruth Britto , Freddy Cachazo , Bo Feng

We compute two infinite series of tree-level amplitudes with a massive scalar pair and an arbitrary number of gluons. We provide results for amplitudes where all gluons have identical helicity, and amplitudes with one gluon of opposite…

High Energy Physics - Theory · Physics 2009-11-11 Darren Forde , David A. Kosower

We compute the one-loop gluon amplitude for the open twistor string model of Berkovits, using a symmetric form of the vertex operators. We discuss the classical solutions in various topologies and instanton sectors and the canonical…

High Energy Physics - Theory · Physics 2010-10-27 Louise Dolan , Peter Goddard

In this letter, we exploit generalised unitarity in order to calculate the cut-constructible part of one-loop amplitudes in non-supersymmetric Yang-Mills theory. In particular, we rederive the n-gluon MHV amplitudes for both the adjacent…

High Energy Physics - Phenomenology · Physics 2010-02-03 Andreas Brandhuber , Massimiliano Vincon

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 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 use the infrared consistency of one-loop amplitudes in N=4 Yang-Mills theory to derive a compact analytic formula for a tree-level NNMHV gluon scattering amplitude in QCD, the first such formula known. We argue that the IR conditions,…

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

A c++ implementation of the D_s-dimensional unitarity cut algorithm for the numerical evaluation of the virtual contribution to NLO QCD amplitudes is presented. The current version includes an arbitrary number of external gluons with…

High Energy Physics - Phenomenology · Physics 2008-12-17 A. Lazopoulos

We present new recursion relations for tree amplitudes in gauge theory that give very compact formulas. Our relations give any tree amplitude as a sum over terms constructed from products of two amplitudes of fewer particles multiplied by a…

High Energy Physics - Theory · Physics 2008-11-26 Ruth Britto , Freddy Cachazo , Bo Feng

Generalised unitarity techniques are used to calculate the coefficients of box and triangle integral functions of one-loop gluon scattering amplitudes in gauge theories with $N < 4$ supersymmetries. We show that the box coefficients in N=1…

High Energy Physics - Theory · Physics 2008-11-26 Steven J. Bidder , N. E. J. Bjerrum-Bohr , David C. Dunbar , Warren B. Perkins

We propose a new, twistor string theory inspired formalism to calculate loop amplitudes in N=4 super Yang-Mills theory. In this approach, maximal helicity violating (MHV) tree amplitudes of N=4 super Yang-Mills are used as vertices, using…

High Energy Physics - Theory · Physics 2010-04-05 Andreas Brandhuber , Bill Spence , Gabriele Travaglini

We extend the generalized D-dimensional unitarity method for numerical evaluation of one-loop amplitudes by incorporating massive particles. The issues related to extending the spinor algebra to higher dimensions, treatment of external…

High Energy Physics - Phenomenology · Physics 2010-04-21 R. K. Ellis , W. T. Giele , Z. Kunszt , K. Melnikov

We compute the next-to-maximally-helicity-violating one-loop n-gluon amplitudes in N=1 super-Yang-Mills theory. These amplitudes contain three negative-helicity gluons and an arbitrary number of positive-helicity gluons, and constitute the…

High Energy Physics - Theory · Physics 2013-12-19 Alexander Ochirov

Recently, based on the curve-integral formulation for stringy Tr$\phi^3$ amplitudes, a combinatorial formulation for Yang-Mills amplitudes has been proposed which describes gluons using pairs of scalars and produces the $n$-gluon amplitude…

High Energy Physics - Theory · Physics 2025-12-19 Jin Dong , Yong-Xiang Su , Dongyu Yang

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
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