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Related papers: Some analytic results for two-loop scattering ampl…

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Splitting amplitudes govern the behavior of scattering amplitudes at the momenta of external legs become collinear. In this talk we outline the calculation of two-loop splitting amplitudes via the unitarity sewing method. This method…

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

In addition to the superconformal symmetry of the underlying Lagrangian, the scattering amplitudes in planar N=4 super-Yang-Mills theory exhibit a new, dual superconformal symmetry. We address the question of how powerful these symmetries…

High Energy Physics - Theory · Physics 2010-03-17 G. P. Korchemsky , E. Sokatchev

We compute all planar two-loop six-point Feynman integrals entering scattering observables in massless gauge theories such as QCD. A central result of this paper is the formulation of the differential-equations method under the algebraic…

High Energy Physics - Phenomenology · Physics 2024-12-31 Samuel Abreu , Pier Francesco Monni , Ben Page , Johann Usovitsch

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 the first numerical results for the two-loop helicity amplitudes for the scattering of four partons and a W-boson in QCD. We use a finite field sampling method to reduce directly from Feynman diagrams to the coefficients of a set…

High Energy Physics - Phenomenology · Physics 2019-07-01 Heribertus Bayu Hartanto , Simon Badger , Christian Brønnum-Hansen , Tiziano Peraro

We compute four-point scattering amplitudes in $\mathcal{N}=2$ SCQCD with general external matter configurations using $\mathcal{N}=1$ superspace Feynman diagrams, at one loop in the general case and up to two loops in the fundamental…

High Energy Physics - Theory · Physics 2015-01-22 Marta Leoni , Andrea Mauri , Alberto Santambrogio

We exploit the recently described property of cluster adjacency for scattering amplitudes in planar $\mathcal{N}=4$ super Yang-Mills theory to construct the symbol of the four-loop NMHV heptagon amplitude. We use a manifestly cluster…

High Energy Physics - Theory · Physics 2020-04-16 James Drummond , Jack Foster , Ömer Gürdoğan , Georgios Papathanasiou

We present a new method for computing multi-loop scattering amplitudes in Quantum Field Theory. It extends the Generalized Unitarity method by constraining not only the integrand of the amplitude but also its full integrated form. Our…

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

Over the past two years, the use of on-shell techniques has deepened our understanding of the S-matrix of gauge theories and led to the calculation of many new scattering amplitudes. In these notes we review a particular on-shell method…

High Energy Physics - Theory · Physics 2017-08-23 Andreas Brandhuber , Gabriele Travaglini

We give a closed-form, prescriptive representation of all-multiplicity two-loop MHV amplitude integrands in fully-color-dressed (non-planar) maximally supersymmetric Yang-Mills theory.

High Energy Physics - Theory · Physics 2021-06-01 Jacob L. Bourjaily , Enrico Herrmann , Cameron Langer , Andrew J. McLeod , Jaroslav Trnka

The infrared exponentiation properties of dimensionally-regularized multi-loop scattering amplitudes are typically hidden at the level of the integrand, materializing only after integral evaluation. We address this long-standing problem by…

High Energy Physics - Theory · Physics 2019-07-22 Robert M. Schabinger

We use the leading singularity technique to determine the planar six-particle two-loop MHV amplitude in N=4 super Yang-Mills in terms of a simple basis of integrals. Our result for the parity even part of the amplitude agrees with the one…

High Energy Physics - Theory · Physics 2009-02-05 Freddy Cachazo , Marcus Spradlin , Anastasia Volovich

We present an integral representation for the parity-even part of the two-loop six-point planar NMHV amplitude in terms of Feynman integrals which have simple transformation properties under the dual conformal symmetry. We probe the dual…

High Energy Physics - Theory · Physics 2011-03-22 D. A. Kosower , R. Roiban , C. Vergu

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

By converting the Asymptotic Bethe Ansatz (ABA) of ${\cal N}=4$ SYM into non-linear integral equations, we find 2D scattering amplitudes of excitations on top of the GKP vacuum. We prove that this is a suitable and powerful set-up for the…

High Energy Physics - Theory · Physics 2015-06-16 Davide Fioravanti , Simone Piscaglia , Marco Rossi

We compute the two-loop four-point MHV form factor of the stress-tensor supermultiplet in planar ${\cal N}=4$ super Yang-Mills (SYM). This form factor is analogous to the Higgs plus four-gluon amplitudes in the heavy-top limit of QCD when…

High Energy Physics - Theory · Physics 2025-03-11 Yuanhong Guo , Lei Wang , Gang Yang , YiXiong Yin

We present the values of the complete set of planar four-point Master Integrals needed for massive Bhabha scattering in the limit of fixed angle and high energy at the two-loop level. The integrals have been calculated using direct…

High Energy Physics - Phenomenology · Physics 2010-04-05 M. Czakon , J. Gluza , T. Riemann

The precise form of the multi-Regge asymptotics of the two-loop six-point MHV amplitude in N = 4 Super-Yang-Mills theory has been a subject of recent controversy. In this paper we utilize the amplitude/Wilson loop correspondence to obtain…

High Energy Physics - Theory · Physics 2010-02-25 Robert M. Schabinger

We compare the two-loop corrections to the finite part of the light-like hexagon Wilson loop with the recent numerical results for the finite part of the MHV six-gluon amplitude in N=4 SYM theory by Bern, Dixon, Kosower, Roiban, Spradlin,…

High Energy Physics - Theory · Physics 2009-04-17 J. M. Drummond , J. Henn , G. P. Korchemsky , E. Sokatchev

In this paper, we present the two-loop correction to scattering amplitudes in three-dimensional $\mathcal{N}=6$ Chern-Simons matter theory. We use eight-point case as our main example, but the method generalizes to all multiplicities. The…

High Energy Physics - Theory · Physics 2023-02-09 Song He , Yu-tin Huang , Chia-Kai Kuo , Zhenjie Li