English
Related papers

Related papers: Analytic results for two-loop Yang-Mills

200 papers

We calculate all planar contributions to the two-loop massless helicity amplitudes for the process $q\bar q\to \gamma\gamma\gamma$. The results are presented in fully analytic form in terms of the functional basis proposed recently by…

High Energy Physics - Phenomenology · Physics 2021-08-25 Herschel A. Chawdhry , Michal Czakon , Alexander Mitov , Rene Poncelet

We present the two-loop helicity amplitudes for the scattering of massless quarks in QCD. We use projector techniques to compute the coefficients of the general four-quark amplitude at up to two-loops in conventional dimensional…

High Energy Physics - Phenomenology · Physics 2009-11-10 E. W. N. Glover

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

We compute the two-loop helicity amplitudes for the production of three photons at hadron colliders in QCD at leading-color. Using the two-loop numerical unitarity method coupled with analytic reconstruction techniques, we obtain the…

High Energy Physics - Phenomenology · Physics 2021-01-20 S. Abreu , B. Page , E. Pascual , V. Sotnikov

We conjecture a simple relationship between the one-loop maximally helicity violating gluon amplitudes of ordinary QCD (all helicities identical) and those of N=4 supersymmetric Yang-Mills (all but two helicities identical). Because the…

High Energy Physics - Theory · Physics 2009-07-09 Z. Bern , L. Dixon , D. C. Dunbar , D. A. Kosower

Planar L-loop maximally helicity violating amplitudes in N = 4 supersymmetric Yang-Mills theory are believed to possess the remarkable property of satisfying iteration relations in L. We propose a simple new method for studying the…

High Energy Physics - Theory · Physics 2009-11-11 Freddy Cachazo , Marcus Spradlin , Anastasia Volovich

We present the two-loop pure gauge contribution to the gluon-gluon scattering amplitude with maximal helicity violation. Our construction of the amplitude does not rely directly on Feynman diagrams, but instead uses its analytic properties…

High Energy Physics - Phenomenology · Physics 2011-06-27 Z. Bern , L. Dixon , D. A. Kosower

Unitarity cuts are widely used in analytic computation of loop amplitudes in gauge theories such as QCD. We expand upon the technique introduced in hep-ph/0503132 to carry out any finite unitarity cut integral. This technique naturally…

High Energy Physics - Phenomenology · Physics 2011-05-05 Ruth Britto , Bo Feng , Pierpaolo Mastrolia

We review the recently developed bootstrap method for the computation of high-multiplicity QCD amplitudes at one loop. We illustrate the general algorithm step by step with a six-point example. The method combines (generalized) unitarity…

High Energy Physics - Phenomenology · Physics 2008-11-26 Carola F. Berger

We compute the leading colour contributions to five-gluon scattering at two loops in massless QCD. The integrands of all independent helicity amplitudes are evaluated using d-dimensional generalised unitarity cuts and finite field…

High Energy Physics - Phenomenology · Physics 2018-03-07 Simon Badger , Christian Brønnum-Hansen , Heribertus Bayu Hartanto , Tiziano Peraro

We present a method for the integrand-level reduction of two-loop helicity amplitudes in both $d=4-2\epsilon$ and $d=4$ dimensions. The amplitude is expressed in terms of a set of Feynman integrals and their coefficients that depend on the…

High Energy Physics - Phenomenology · Physics 2025-11-14 Giuseppe Bevilacqua , Dhimiter Canko , Costas Papadopoulos , Aris Spourdalakis

We present the master integrals relevant for computing the complete set of leading-colour analytic helicity amplitudes for top-quark pair production via gluon fusion at two-loops in QCD. We include corrections due to massive fermion loops…

High Energy Physics - Phenomenology · Physics 2021-11-01 Ekta Chaubey

Virtual two-loop corrections to scattering amplitudes are a key ingredient to precision physics at collider experiments. We compute the full set of planar master integrals relevant to five-point functions in massless QCD, and use these to…

High Energy Physics - Phenomenology · Physics 2016-04-18 T. Gehrmann , J. M. Henn , N. A. Lo Presti

We compute the three-loop corrections to the helicity amplitudes for $q\bar{q}\to Q\bar{Q}$ scattering in massless QCD. In the Lorentz decomposition of the scattering amplitude we avoid evanescent Lorentz structures and map the…

High Energy Physics - Phenomenology · Physics 2024-11-06 Fabrizio Caola , Amlan Chakraborty , Giulio Gambuti , Andreas von Manteuffel , Lorenzo Tancredi

In this talk we review the recent computation of the five- and six-gluon two-loop amplitudes in Yang-Mills theory using local integrands which make the infrared pole structure manifest. We make some remarks on the connection with BCJ…

High Energy Physics - Phenomenology · Physics 2016-07-04 Simon Badger , Gustav Mogull , Tiziano Peraro

We present the two-loop QCD helicity amplitudes for quark-quark and quark-antiquark scattering. These amplitudes are relevant for next-to-next-to-leading order corrections to (polarized) jet production at hadron colliders. We give the…

High Energy Physics - Phenomenology · Physics 2014-01-27 Abilio De Freitas , Zvi Bern

We review the extension of modern techniques for the calculation of helicity amplitudes in QCD to massive particles. The focus is on the use of supersymmetric Ward identites that relate amplitudes with massive quarks to those with massive…

High Energy Physics - Phenomenology · Physics 2008-11-26 Rutger Boels , Christian Schwinn , Stefan Weinzierl

We describe techniques that simplify the calculation of one-loop QCD amplitudes with many external legs, which are needed for next-to-leading-order (NLO) corrections to multi-jet processes. The constraints imposed by perturbative unitarity,…

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

I discuss the recent advances in the computation of two-loop scattering amplitudes for five-particle processes. The latter are fundamental ingredients to obtain predictions at the next-to-next-to-leading order (NNLO) in QCD for many…

High Energy Physics - Phenomenology · Physics 2023-10-09 Simone Zoia

We present the two-loop helicity amplitudes contributing to the next-to-next-to-leading order QCD predictions for W-boson production in association with two photons at the Large Hadron Collider. We derived compact analytic expressions for…

High Energy Physics - Phenomenology · Physics 2024-09-27 Simon Badger , Heribertus Bayu Hartanto , Zihao Wu , Yang Zhang , Simone Zoia