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Related papers: One-loop gauge invariant amplitudes with a space-l…

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We compute the part of the two-loop virtual amplitude for the process $gg \to V_1 V_2 \to (l_1 \bar l'_{1}) (l_2 \bar l'_2)$, where $V_{1,2}$ are arbitrary electroweak gauge bosons, that receives contributions from loops of massless quarks.…

High Energy Physics - Phenomenology · Physics 2015-04-02 Fabrizio Caola , Johannes M. Henn , Kirill Melnikov , Alexander V. Smirnov , Vladimir A. Smirnov

We propose that loop integrals with internal heavy particles can be evaluated by expanding in the limit of small external masses. This provides a systematically improvable approximation to the integrals in the entire phase space, and works…

High Energy Physics - Phenomenology · Physics 2019-02-05 Xiaofeng Xu , Li Lin Yang

We develop an algorithm of polynomial complexity for evaluating one-loop amplitudes with an arbitrary number of external particles. The algorithm is implemented in the Rocket program. Starting from particle vertices given by Feynman rules,…

High Energy Physics - Phenomenology · Physics 2009-05-05 W. T. Giele , G. Zanderighi

Generalized Parton Distributions (GPDs) carry information on the internal structure of hadrons such as the angular momentum of quarks and gluons, or their spacelike distribution. They can be experimentally studied in exclusive experiments…

High Energy Physics - Phenomenology · Physics 2021-08-13 Oskar Grocholski

In view of the forthcoming High-Luminosity phase of the LHC, next-to-next-to-next-to-leading (N$^3$LO) calculations for the most phenomenologically relevant processes become necessary. In this work, we take the first step towards this goal…

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

In the framework of the gluon-gluon fusion process for Higgs boson production there are two different prescriptions. They are given by the exact process where the gluons couple via top-quark loops to the Higgs boson and by the approximation…

High Energy Physics - Phenomenology · Physics 2009-11-11 J. Smith , W. L. van Neerven

We present predictions for gluon-fusion Higgs boson production in association with one jet at next-to-leading order in QCD. The calculation is performed retaining the full dependence on the top-quark mass. The two-loop integrals appearing…

High Energy Physics - Phenomenology · Physics 2018-07-20 Matthias Kerner

We consider QCD radiative corrections to Higgs boson pair production through gluon fusion in proton collisions. We combine the exact next-to-leading order (NLO) contribution, which features two-loop virtual amplitudes with the full…

High Energy Physics - Phenomenology · Physics 2018-06-13 Massimiliano Grazzini , Gudrun Heinrich , Stephen Jones , Stefan Kallweit , Matthias Kerner , Jonas M. Lindert , Javier Mazzitelli

In this talk we discuss an algorithm for the numerical calculation of one-loop QCD amplitudes and present results at next-to-leading order for jet observables in electron-positron annihilation calculated with the above-mentioned method. The…

High Energy Physics - Phenomenology · Physics 2011-12-16 S. Becker , D. Goetz , C. Reuschle , C. Schwan , S. Weinzierl

We calculate the three-loop matching coefficient $C_{HH}$, required for a consistent description of Higgs boson pair production in gluon fusion through next-to-next-to-leading order QCD in the heavy top quark approximation. We also compute…

High Energy Physics - Phenomenology · Physics 2015-06-22 Jonathan Grigo , Kirill Melnikov , Matthias Steinhauser

Accurate and efficient amplitude predictions are essential for precision studies of multi-jet processes at the LHC. We introduce a novel neural network architecture that predicts multi-jet amplitudes by leveraging the Catani-Seymour…

High Energy Physics - Phenomenology · Physics 2025-12-16 Luca Beccatini , Fabio Maltoni , Olivier Mattelaer , Ramon Winterhalder

In this talk, we present the first, numerically stable, results for the one-loop amplitudes needed for computing W,Z + 3 jet cross sections at the LHC to next-to-leading order in the QCD coupling. We implemented these processes in BlackHat,…

High Energy Physics - Phenomenology · Physics 2008-08-08 C. F. Berger , Z. Bern , L. J. Dixon , F. Febres Cordero , D. Forde , H. Ita , D. A. Kosower , D. Maitre

We present a semi-recursive method for calculating the rational parts of one-loop gravity amplitudes which utilises axial gauge diagrams to determine the non-factorising pieces of the amplitude. This method is used to compute the one-loop…

High Energy Physics - Theory · Physics 2014-11-20 David C. Dunbar , James H. Ettle , Warren B. Perkins

In this talk we present recent next-to-leading order results relevant for LHC phenomenology obtained with the GOLEM method. After reviewing the status of this Feynman diagrammatic approach for multi-leg one-loop calculations we discuss…

High Energy Physics - Phenomenology · Physics 2014-11-18 T. Binoth , A. Guffanti , J. -Ph. Guillet , G. Heinrich , S. Karg , N. Kauer , P. Mertsch , T. Reiter , J. Reuter , G. Sanguinetti

We compute the one-loop QCD amplitudes for the decay of an off-shell vector boson with vector couplings into a quark-antiquark pair accompanied by two gluons keeping, for the first time, all orders in the number of colours. Together with…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. M. Campbell , E. W. N. Glover , D. J. Miller

Several stochastic processes with virtual particles in two dimensional space-time are presented whose mean field equations coincide with Schr\"odinger, Dirac, Klein-Gordon and the quantum mechanic equation for a photon. These processes…

Quantum Physics · Physics 2015-11-03 Alberto C. de la Torre

We present a precise and efficient computation of the two-loop amplitudes entering the Higgs boson pair production process via gluon fusion. Our approach is based on the small-Higgs-mass expansion while keeping the full dependence on the…

High Energy Physics - Phenomenology · Physics 2021-09-29 Guoxing Wang , Yuxuan Wang , Xiaofeng Xu , Yongqi Xu , Li Lin Yang

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 virtual corrections to the production cross section of a Standard Model Higgs boson are computed up to order \alpha_s^4. Using an effective Lagrangian for the limit M_t -> \infty, we evaluate the relevant massless two-loop vertex…

High Energy Physics - Phenomenology · Physics 2009-10-31 Robert V. Harlander

We combine the six-dimensional helicity formalism of Cheung and O'Connell with D-dimensional generalized unitarity to obtain a new formalism for computing one-loop amplitudes in dimensionally regularized QCD. With this procedure, we…

High Energy Physics - Phenomenology · Physics 2013-05-29 Scott Davies