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Related papers: Two-loop QCD helicity amplitudes for massless quar…

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The ability to calculate analytic full-colour two-to-three two-loop helicity amplitudes in massless QCD has been a recent triumph of the field, driving phenomenology towards one percent precision. In this contribution, we focus on the…

High Energy Physics - Phenomenology · Physics 2023-10-31 Ryan Moodie

We analytically compute the two-loop scattering amplitude $gg \to Hg$ assuming that the mass of the quark, that mediates the ggH interaction, is vanishingly small. Our computation provides an important ingredient required to improve the…

High Energy Physics - Phenomenology · Physics 2016-12-02 Kirill Melnikov , Lorenzo Tancredi , Christopher Wever

We use the solutions to the recursion relations for double-off-shell fermion currents to compute helicity amplitudes for $n$-photon scattering and electron-positron annihilation to photons in the massless limit of QED. The form of these…

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

We review recent progress on the calculation of scattering amplitudes in the high-energy limit. We start by illustrating the shockwave formalism, which allows one to calculate amplitudes as iterated solutions of rapidity evolution…

High Energy Physics - Phenomenology · Physics 2021-11-10 Leonardo Vernazza , Giulio Falcioni , Einan Gardi , Niamh Maher , Calum Milloy

In this work, we express the singular part of a scattering amplitude in terms of Feynman integrals compatible with topologies appearing in the bare amplitude, and we choose a basis of locally finite Master Integrals. In two-loop massless…

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

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 consider elastic quark-quark scattering at high energy and fixed transferred momentum. Performing factorization of soft gluon exchanges into Wilson line expectation value we find that there is one-to-one correspondence between high…

High Energy Physics - Phenomenology · Physics 2009-10-28 I. A. Korchemskaya , G. P. Korchemsky

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 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 compute helicity amplitudes for the one-loop QCD corrections to top-quark pair production analytically in terms of a set of uniformly transcendental master integrals. We provide corrections up to $O(\epsilon^2)$ in the dimensional…

High Energy Physics - Phenomenology · Physics 2022-06-29 Simon Badger , Matteo Becchetti , Ekta Chaubey , Robin Marzucca , Francesco Sarandrea

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

The one-loop QCD effective charge $\alpha_s^{eff}$ for quark-quark scattering is derived by diagrammatic resummation of the one-loop amplitude using an arbitary covariant gauge. Except for the particular choice of gauge parameter $\xi =…

High Energy Physics - Phenomenology · Physics 2015-06-25 J. H. Field

We calculate the complete two-loop QCD amplitudes for hadronic $tW$ production by combining analytical and numerical techniques. The amplitudes have been first reduced to master integrals of eight planar and seven non-planar families, which…

High Energy Physics - Phenomenology · Physics 2023-08-02 Long-Bin Chen , Liang Dong , Hai Tao Li , Zhao Li , Jian Wang , Yefan Wang

We address the analytic computation of the two-loop scattering amplitudes for the production of two photons in parton-parton scattering, mediated by loops of heavy quarks. Due to the presence of integrals of elliptic type, both partonic…

High Energy Physics - Phenomenology · Physics 2025-02-04 Matteo Becchetti , Federico Coro , Christoph Nega , Lorenzo Tancredi , Fabian J. Wagner

We show that the chiral algebra bootstrap, which computes form factors of twistorial theories, can help determine two-loop amplitudes in massless QCD. We give an $n$-gluon result for a previously unknown partial amplitude of the two-loop…

High Energy Physics - Theory · Physics 2025-10-24 Anthony Morales

We compute a complete set of independent leading-color two-loop five-parton amplitudes in QCD. These constitute a fundamental ingredient for the next-to-next-to-leading order QCD corrections to three-jet production at hadron colliders. We…

High Energy Physics - Phenomenology · Physics 2019-04-09 S. Abreu , F. Febres Cordero , H. Ita , B. Page , V. Sotnikov

The high-energy factorization of gauge theory scattering amplitudes in terms of universal impact factors and a Reggeized exchange in the $t$-channel, corresponding to a Regge pole in the angular momentum plane, is know to conflict with the…

High Energy Physics - Phenomenology · Physics 2013-12-19 Vittorio Del Duca , Giulio Falcioni , Lorenzo Magnea , Leonardo Vernazza

We compute all helicity amplitudes for four-particle scattering in massless QCD with $n_f$ fermion flavours to next-to-next-to-leading order (NNLO) in perturbation theory. In particular, we consider all possible configurations of external…

High Energy Physics - Phenomenology · Physics 2020-01-23 Taushif Ahmed , Johannes Henn , Bernhard Mistlberger

We compute the integrand of the full-colour, two-loop, five-gluon scattering amplitude in pure Yang-Mills theory with all helicities positive, using generalized unitarity cuts. Tree-level BCJ relations, satisfied by amplitudes appearing in…

High Energy Physics - Phenomenology · Physics 2015-10-16 Simon Badger , Gustav Mogull , Alexander Ochirov , Donal O'Connell

We analyse the high-energy limit of the gluon-gluon scattering amplitude in QCD, and display an intriguing relation between the finite parts of the one-loop gluon impact factor and the finite parts of the two-loop Regge trajectory.

High Energy Physics - Phenomenology · Physics 2018-04-04 Vittorio Del Duca
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