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Related papers: Non-Planar Two-Loop Amplitudes for Five-Parton Sca…

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I review the recent progress in the evaluation of two-loop massive QCD amplitudes necessary for the description of hadronic scattering processes at the LHC. I put a special emphasis on the case of top-quark final states.

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Czakon

We present a semi-numerical algorithm to calculate one-loop virtual corrections to scattering amplitudes. The divergences of the loop amplitudes are regulated using dimensional regularization. We treat in detail the case of amplitudes with…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. K. Ellis , W. T. Giele , G. Zanderighi

We present an alternative method to calculate cross sections for multi-parton scattering processes in the Standard Model at leading order. The helicity amplitudes are computed using recursion relations in the number of particles, based on…

High Energy Physics - Phenomenology · Physics 2008-11-26 Costas G. Papadopoulos , Malgorzata Worek

We present a new procedure using on-shell recursion to determine coefficients of integral functions appearing in one-loop scattering amplitudes of gauge theories, including QCD. With this procedure, coefficients of integrals, including…

High Energy Physics - Phenomenology · Physics 2009-11-11 Zvi Bern , N. E. J. Bjerrum-Bohr , David C. Dunbar , Harald Ita

We compute the planar three-loop Quantum Chromodynamics (QCD) corrections to the helicity amplitudes involving a vector boson $V=Z,W^\pm,\gamma^*$, two quarks and a gluon. These amplitudes are relevant to vector-boson-plus-jet production at…

High Energy Physics - Phenomenology · Physics 2023-12-07 Thomas Gehrmann , Petr Jakubčík , Cesare Carlo Mella , Nikolaos Syrrakos , Lorenzo Tancredi

We compute squared matrix elements at next-to-next-to-leading order in perturbative quantum chromodynamics for the production of two or three (on- or off-shell) photons mediated via (light or heavy) quark loops. Our method handles all cases…

High Energy Physics - Phenomenology · Physics 2025-10-22 Dario Kermanschah , Matilde Vicini

We present a numerical implementation for virtual corrections to multi-jet production at Next-to-Leading order. Using the algorithm of generalised unitarity we compute primitive amplitudes from tree-level input. These basic ingredients are…

High Energy Physics - Phenomenology · Physics 2012-01-06 Simon Badger , Benedikt Biedermann , Peter Uwer

The rational parts of 6-gluon one-loop amplitudes with scalars circulating in the loop are computed by using the newly developed method for computing the rational parts directly from Feynman integrals. We present the analytic results for…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zhi-Guang Xiao , Gang Yang , Chuan-Jie Zhu

We report on the two-loop amplitude computation for the mixed QCD-electroweak corrections to the process $gg \to Hg$, with exact dependence on the electroweak boson masses. This amplitude has been employed in the computation of…

High Energy Physics - Phenomenology · Physics 2022-05-11 Matteo Becchetti , Francesco Moriello , Armin Schweitzer

We present the NNLO QCD virtual corrections for qurak-antiquark -> gluon photon, quark-antiquark -> photon photon and the NNLO QED virtual corrections for electron positron -> photon photon and all processes related by crossing symmetry. We…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. Anastasiou , E. W. N. Glover , M. E. Tejeda-Yeomans

We propose to make use of the off-shell recursive relations with the color-flow decomposition in the calculation of QCD amplitudes on MadGraph. We introduce colored quarks and their interactions with nine gluons in the color-flow basis plus…

High Energy Physics - Phenomenology · Physics 2011-06-08 Kaoru Hagiwara , Yoshitaro Takaesu

We compute theoretical predictions for the production of a W-boson in association with a bottom-quark pair at hadron colliders at next-to-next-to-leading order (NNLO) in QCD, including the leptonic decay of the W-boson, while treating the…

High Energy Physics - Phenomenology · Physics 2022-05-17 Heribertus Bayu Hartanto , Rene Poncelet , Andrei Popescu , Simone Zoia

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

We present the analytic and compact two-loop helicity amplitudes for QCD and QED corrections to the light-by-light scattering process with massive internal fermions. We express the master integrals either in terms of multiple polylogarithms…

High Energy Physics - Phenomenology · Physics 2024-03-22 Ajjath A H , Ekta Chaubey , Hua-Sheng Shao

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. We explain how a supersymmetry-inspired organization works…

High Energy Physics - Phenomenology · Physics 2007-05-23 L. Dixon

Splitting amplitudes are universal functions governing the collinear behavior of scattering amplitudes for massless particles. We compute the two-loop g -> gg splitting amplitudes in QCD, N=1, and N=4 super-Yang-Mills theories, which…

High Energy Physics - Phenomenology · Physics 2010-03-25 Zvi Bern , Lance J. Dixon , David A. Kosower

We report on a technique for evaluating finite unitarity cut for one-loop amplitudes in gauge theories, and discuss its application to the cut-constructible part of six-gluon amplitude in QCD.

High Energy Physics - Phenomenology · Physics 2009-11-11 Pierpaolo Mastrolia

We present an expression for the QCD amplitude for a general hard scattering process with any number of soft gluon emissions, to one-loop accuracy. The amplitude is written in two different but equivalent ways: as a product of operators…

High Energy Physics - Phenomenology · Physics 2016-06-01 René Ángeles-Martínez , Jeffrey R. Forshaw , Michael H. Seymour

We compute the helicity amplitudes for the processes $gg\to Zg$ and $gg\to Z\gamma$ to two loops in massless QCD. The perturbative expansion of these processes starts only at the one-loop level, such that our results are a crucial…

High Energy Physics - Phenomenology · Physics 2023-08-21 Thomas Gehrmann , Lorenzo Tancredi , Erich Weihs

We present a calculation of the bosonic contribution to the two-loop mixed QCD-electroweak scattering amplitudes for $Z$-boson production in association with one hard jet at hadron colliders. We employ a method to calculate amplitudes in…

High Energy Physics - Phenomenology · Physics 2024-09-30 Piotr Bargiela , Fabrizio Caola , Herschel Chawdhry , Xiao Liu