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Related papers: Recent Progress in One-Loop Multi-Parton Calculati…

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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

We present a semi-numerical method to compute one-loop corrections to multi-leg processes. We apply the method to the study of Higgs plus four parton and six gluon amplitudes.

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Zanderighi

Many search strategies for the Standard Model Higgs boson apply specific selection criteria on hadronic jets observed in association with the Higgs boson decay products, either in the form of a jet veto, or by defining event samples…

High Energy Physics - Phenomenology · Physics 2015-06-03 T. Gehrmann , M. Jaquier , E. W. N. Glover , A. Koukoutsakis

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

We present examples of on-shell recurrence relations for determining rational functions appearing in one-loop QCD amplitudes. In particular, we give relations for one-loop QCD amplitudes with all legs of positive helicity, or with one leg…

High Energy Physics - Theory · Physics 2010-11-15 Zvi Bern , Lance J. Dixon , David A. Kosower

We present the tree-level amplitudes involving one, two and three photons that are required for next-to-leading order QCD calculations of production rates of three final-state particles. We also present the required one-loop amplitudes in…

High Energy Physics - Phenomenology · Physics 2009-10-31 Vittorio Del Duca , William B. Kilgore , Fabio Maltoni

We compute the planar part of the two-loop five gluon amplitude with all helicities positive. To perform the calculation we develop a D-dimensional generalized unitarity procedure allowing us to reconstruct the amplitude by cutting into…

High Energy Physics - Phenomenology · Physics 2015-07-21 Simon Badger , Hjalte Frellesvig , Yang Zhang

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

In this paper we discuss techniques, which lead to a significant improvement of the efficiency of the Monte Carlo integration, when one-loop QCD amplitudes are calculated numerically with the help of the subtraction method and contour…

High Energy Physics - Phenomenology · Physics 2015-06-05 Sebastian Becker , Christian Reuschle , Stefan Weinzierl

In this thesis, we present recent advances at the precision frontier of higher-order quantum chromodynamics (QCD) calculations. We consider massless two-loop five-point amplitudes, with a particular focus on diphoton-plus-jet production…

High Energy Physics - Phenomenology · Physics 2022-10-14 Ryan Moodie

Recent progress in unitarity techniques for one-loop scattering amplitudes makes a numerical implementation of this method possible. We present a 4-dimensional unitarity method for calculating the cut-constructible part of amplitudes and…

High Energy Physics - Phenomenology · Physics 2009-09-17 R. K. Ellis , W. T. Giele , Z. Kunszt

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 calculate the next-to-leading order QCD corrections to the spin-dependent cross section for single-inclusive hadron production in hadronic collisions. This process will be soon studied experimentally at RHIC, providing a tool to unveil…

High Energy Physics - Phenomenology · Physics 2009-11-07 Daniel de Florian

We present a C++ library for the numerical evaluation of one-loop virtual corrections to multi-jet production in massless QCD. The pure gluon primitive amplitudes are evaluated using NGluon. A generalized unitarity reduction algorithm is…

High Energy Physics - Phenomenology · Physics 2015-06-11 Simon Badger , Benedikt Biedermann , Peter Uwer , Valery Yundin

We compute the one-loop corrections to \tth up to order $\mathcal{O}(\epsilon^2)$ in the dimensional regularization parameter. We apply the projector method to compute polarized amplitudes, which generalize massless helicity amplitudes to…

High Energy Physics - Phenomenology · Physics 2023-12-18 Federico Buccioni , Philipp Alexander Kreer , Xiao Liu , Lorenzo Tancredi

The state-of-the-art in current two-loop QCD amplitude calculations is at five-particle scattering. Computing two-loop six-particle processes requires knowledge of the corresponding one-loop amplitudes to higher orders in the dimensional…

High Energy Physics - Theory · Physics 2023-02-08 Johannes M. Henn , Antonela Matijašić , Julian Miczajka

The numerical unitarity approach has been important for obtaining reliable QCD predictions for the LHC. Here I discuss the extension of the approach beyond the leading quantum corrections for computing multi-loop amplitudes. The numerical…

High Energy Physics - Phenomenology · Physics 2017-03-27 Harald Ita

In this talk we examine how one-loop soft and collinear splitting functions occur in the calculation of next-to-next-to-leading order (NNLO) corrections to production rates, and we present the one-loop gluon soft and splitting functions,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Zvi Bern , Vittorio Del Duca , William B. Kilgore , Carl R. Schmidt

In this article we present a method to generate analytic expressions for the integral coefficients of loop amplitudes using numerical evaluations only. We use high-precision arithmetic to explore the singularity structure of the…

High Energy Physics - Phenomenology · Physics 2023-10-09 Giuseppe De Laurentis , Daniel Maître

Processes involving electroweak vector bosons in association with jets are crucial for precision studies of the Standard Model at the Large Hadron Collider. Accurate predictions for the process $pp\rightarrow V(\rightarrow\bar\ell\ell)jj$…

High Energy Physics - Phenomenology · Physics 2024-09-25 Giuseppe De Laurentis
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