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Related papers: Two-Loop N=4 Supersymmetric Amplitudes and QCD

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The infrared singularities of gravitational amplitudes are one-loop exact, in that higher-loop divergences are characterized by the exponential of the one-loop divergence. We show that the contributions to SU(N) gauge-theory amplitudes that…

High Energy Physics - Theory · Physics 2015-06-12 Stephen G. Naculich , Horatiu Nastase , Howard J. Schnitzer

We describe a general method that enables us to obtain all the singular terms of helicity amplitudes of n-parton processes at one loop. The algorithm uses helicity amplitudes at tree level and simple color algebra. We illustrate the method…

High Energy Physics - Phenomenology · Physics 2009-10-28 Zoltan Kunszt , Adrian Signer , Zoltan Trocsanyi

Planar gluon amplitudes in N=4 SYM are remarkably similar to expectation values of Wilson loops made of light-like segments. We argue that the latter can be determined by making use of the conformal symmetry of the gauge theory, broken by…

High Energy Physics - Theory · Physics 2009-11-18 J. M. Drummond , J. Henn , G. P. Korchemsky , E. Sokatchev

We consider one-loop five-point QCD amplitudes in next-to-multi-Regge kinematics, and evaluate the one-loop impact factor for the emission of two gluons. This is the last ingredient which is necessary to evaluate the gluon-jet impact factor…

High Energy Physics - Phenomenology · Physics 2021-06-30 Marc Canay , Vittorio Del Duca

We have studied the recently completed analytic all-N expressions for the four-loop anomalous dimensions corresponding to the next-to-next-to-next-to-leading order splitting functions for the non-singlet quark distribution in perturbative…

High Energy Physics - Phenomenology · Physics 2026-05-06 S. Moch , A. Vogt

We present the complete two-loop corrections in massless QCD for the production of two photons and a jet, taking into account all color structures. In particular, we analytically compute all two-loop helicity amplitudes for the…

High Energy Physics - Phenomenology · Physics 2022-01-05 Bakul Agarwal , Federico Buccioni , Andreas von Manteuffel , Lorenzo Tancredi

We derive constraints on the color-ordered amplitudes of the L-loop four-point function in SU(N) gauge theories that arise solely from the structure of the gauge group. These constraints generalize well-known group theory relations, such as…

High Energy Physics - Theory · Physics 2015-05-30 Stephen G. Naculich

The self-couplings of the electroweak gauge bosons are probed at hadron colliders through the production of a massive gauge boson and a photon. To extend the theoretical description of this type of final states towards…

High Energy Physics - Phenomenology · Physics 2020-12-09 Thomas Gehrmann , Lorenzo Tancredi

We present the two-loop matrix elements for the scattering of two gluons into two photons in QCD. These matrix elements will enter into improved estimates of the QCD background to Higgs production at the LHC when the Higgs decays into two…

High Energy Physics - Phenomenology · Physics 2010-02-03 Z. Bern , A. De Freitas , L. Dixon

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 review recent developments in the calculation of QCD loop amplitudes with several external legs, and their application to next-to-leading order jet production cross-sections. When a number of calculational tools are combined together ---…

High Energy Physics - Phenomenology · Physics 2007-05-23 Z. Bern , L. Dixon , D. A. Kosower , A. Signer

We show how Supersymmetric Ward identities can be used to obtain amplitudes involving gluinos or adjoint scalars from purely gluonic amplitudes. We obtain results for all one-loop six-point NMHV amplitudes in $\NeqFour$ Super Yang-Mills…

High Energy Physics - Theory · Physics 2009-11-11 Steven J. Bidder , David C. Dunbar , Warren B. Perkins

In this paper we study the one- and two-loop corrections to the four-point amplitude of N=6 Chern-Simons matter theory. Using generalized unitarity methods we express the one- and two-loop amplitudes in terms of dual-conformal integrals.…

High Energy Physics - Theory · Physics 2015-05-28 Wei-Ming Chen , Yu-tin Huang

We apply the solution to the recursion relation for the double-off-shell quark current to the problem of computing one loop amplitudes with an arbitrary number of gluons. We are able to compute amplitudes for photon-gluon scattering,…

High Energy Physics - Phenomenology · Physics 2009-10-22 Gregory Mahlon

We study the first non-planar correction to gluon scattering amplitudes in ${\cal N}=4$ SYM theory. The correction takes the form of a double trace partial amplitude and is suppressed by one power of $1/N$ with respect to the leading single…

High Energy Physics - Theory · Physics 2018-09-26 Roy Ben-Israel , Alexander G. Tumanov , Amit Sever

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

In this talk I review three topics: (i) Heterotic strings from N=1 gauge theories; (ii) Planar equivalence and emergent center symmetry in QCD-like theories; (iii) Exact result for gluon scattering amplitudes in N=4 (dual conformality).

High Energy Physics - Theory · Physics 2009-02-18 M. Shifman

We develop an iterative method for constructing four-dimensional generalized unitarity cuts in $\mathcal{N} = 2$ supersymmetric Yang-Mills (SYM) theory coupled to fundamental matter hypermultiplets ($\mathcal{N} = 2$ SQCD). For iterated…

High Energy Physics - Theory · Physics 2019-10-08 Gregor Kälin , Gustav Mogull , Alexander Ochirov

Recent progress in unitarity techniques for one-loop scattering amplitudes makes a numerical implementation of this method possible. We present a 4-dimensional unitarity method for calculating the cut-constructible part of amplitudes and…

High Energy Physics - Phenomenology · Physics 2009-09-17 R. K. Ellis , W. T. Giele , Z. Kunszt

A study of the colour-ordered one-loop amplitudes in N=4 SYM reveals a surprising property: numerically, the amplitudes have an Approximately Universal form A^{1-loop}_n ~ A^{tree}_n \times U_n, where U_n is helicity independent. This form…

High Energy Physics - Theory · Physics 2009-03-27 David C. Dunbar , James H. Ettle , Warren B. Perkins