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Related papers: Two-loop QCD Amplitudes from the Chiral Algebra Bo…

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We present the first numerical computation of two-loop amplitudes based on the unitarity method. As a proof of principle, we compute the four-gluon process. We discuss the new method, analyze its numerical properties and apply it to…

High Energy Physics - Phenomenology · Physics 2017-10-11 S. Abreu , F. Febres Cordero , H. Ita , M. Jaquier , B. Page , M. Zeng

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 helicity amplitudes for $q\bar{q} \to gg$ and its crossed partonic channels, in massless QCD. Our analytical results provide a non-trivial check of the color quadrupole contribution to the infrared poles for…

High Energy Physics - Phenomenology · Physics 2023-01-04 Fabrizio Caola , Amlan Chakraborty , Giulio Gambuti , Andreas von Manteuffel , Lorenzo Tancredi

We compute the two-loop QCD corrections to $q g \to H q$ and $q \bar{q} \to H g$ amplitudes mediated by loops of nearly massless quarks. These amplitudes provide the last missing ingredient required to compute the NLO QCD corrections to the…

High Energy Physics - Phenomenology · Physics 2017-03-22 Kirill Melnikov , Lorenzo Tancredi , Christopher Wever

We present results for the two-loop helicity amplitudes entering the NLO QCD corrections to the production of a Higgs boson in association with a $Z$-boson in gluon fusion. The two-loop integrals, involving massive top quarks, are…

High Energy Physics - Phenomenology · Physics 2021-03-18 Long Chen , Gudrun Heinrich , Stephen P. Jones , Matthias Kerner , Jonas Klappert , Johannes Schlenk

We study the factorisation properties of one-loop scattering amplitudes in the triple collinear limit and extract the universal splitting amplitudes for processes initiated by a gluon. The splitting amplitudes are derived from the analytic…

High Energy Physics - Phenomenology · Physics 2015-07-20 Simon Badger , Francesco Buciuni , Tiziano Peraro

We study the photon-quark-quark and Higgs-gluon-gluon form factors for on-shell massless quarks and gluons in perturbative QCD. Previous third-order results for the quark case are extended by calculating the fermion-loop contributions up to…

High Energy Physics - Phenomenology · Physics 2010-04-05 S. Moch , J. A. M. Vermaseren , A. Vogt

We present complete two-loop radiative corrections to the graviton-quark-antiquark form factor G^* \rightarrow q \overline q and graviton-gluon-gluon form factor G^* \rightarrow g g in SU(N) gauge theory with n_f light flavours using…

High Energy Physics - Phenomenology · Physics 2014-02-13 Daniel de Florian , Maguni Mahakhud , Prakash Mathews , Javier Mazzitelli , V. Ravindran

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

The planar three-gluon form factor for the chiral stress tensor operator in planar maximally supersymmetric Yang-Mills theory is an analog of the Higgs-to-three-gluon scattering amplitude in QCD. The amplitude (symbol) bootstrap program has…

High Energy Physics - Theory · Physics 2025-04-17 Tianji Cai , François Charton , Kyle Cranmer , Lance J. Dixon , Garrett W. Merz , Matthias Wilhelm

We present the fully integrated form of the two-loop four-gluon amplitude in $\mathcal{N} = 2$ supersymmetric quantum chromodynamics with gauge group SU$(N_c)$ and with $N_f$ massless supersymmetric quarks (hypermultiplets) in the…

High Energy Physics - Theory · Physics 2019-12-18 Claude Duhr , Henrik Johansson , Gregor Kälin , Gustav Mogull , Bram Verbeek

We compute the two-loop corrections to the massless quark form factor $\gamma^* \to q\bar q$ and gluon form factor $H\to gg$ to all orders in the dimensional regularisation parameter $\epsilon=(4-d)/2$. The two-loop contributions to the…

High Energy Physics - Phenomenology · Physics 2021-11-04 T. Gehrmann , T. Huber , D. Maitre

The computation of two-loop amplitudes for the production of multiple Higgs and electroweak gauge bosons via gluon fusion with exact dependence on quark masses relies primarily on numerical methods. We propose a framework that enables their…

High Energy Physics - Phenomenology · Physics 2024-11-13 Charalampos Anastasiou , Julia Karlen , George Sterman , Aniruddha Venkata

We describe the calculation of the three-loop QCD corrections to quark and gluon form factors. The relevant three-loop Feynman diagrams are evaluated and the resulting three-loop Feynman integrals are reduced to a small set of known master…

High Energy Physics - Phenomenology · Physics 2023-11-15 T. Gehrmann , E. W. N. Glover , T. Huber , N. Ikizlerli , C. Studerus

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 review recent developments for the calculation of Born amplitudes in QCD. This includes the computation of gluon helicity amplitudes from MHV vertices and an approach based on scalar propagators and a set of three- and four-valent…

High Energy Physics - Theory · Physics 2015-06-26 Christian Schwinn , Stefan Weinzierl

Using cutting techniques we obtain the two-loop N=4 super-Yang-Mills helicity amplitudes for four-gluon scattering in terms of scalar integral functions. The N=4 amplitudes are considerably simpler than corresponding QCD amplitudes and…

High Energy Physics - Phenomenology · Physics 2009-10-30 Z. Bern , J. S. Rozowsky , B. Yan

We present the two-loop virtual QCD corrections to the production of heavy quarks in gluon fusion. The results are exact in the limit when all kinematical invariants are large compared to the mass of the heavy quark up to terms suppressed…

High Energy Physics - Phenomenology · Physics 2010-04-05 M. Czakon , A. Mitov , S. Moch

There is a special set of massless four-dimensional gauge theories which admit local and gauge-anomaly-free uplifts to twistor space; we call such theories twistorial. In twistorial theories, generalized towers of soft modes (including…

High Energy Physics - Theory · Physics 2025-08-20 Víctor E. Fernández , Natalie M. Paquette

We present on the use of on-shell recursion relations. These can be used not only for calculating tree amplitudes, including those with masses, but also to compute analytically the missing rational terms of one-loop QCD amplitudes. Combined…

High Energy Physics - Phenomenology · Physics 2017-08-23 Darren Forde