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

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In this talk we discuss recent progress concerning precise predictions for the LHC. We give a status report of three applications of our method to deal with multi-leg one-loop amplitudes: The interference term of Higgs production by gluon-…

High Energy Physics - Phenomenology · Physics 2009-04-14 T. Binoth , T. Reiter , J. R. Andersen , G. Heinrich , J. M. Smillie , J. -Ph. Guillet , G. Sanguinetti , S. Karg , N. Kauer

Achieving a precise description of multi-parton final states is crucial for many analyses at LHC. In this contribution we review the main features of the HELAC-NLO system for NLO QCD calculations. As a case study, NLO QCD corrections for tt…

High Energy Physics - Phenomenology · Physics 2010-12-13 G. Bevilacqua , M. Czakon , M. V. Garzelli , A. van Hameren , Y. Malamos , C. G. Papadopoulos , R. Pittau , M. Worek

We present an explicit expression for a particular $n$-gluon two loop scattering partial amplitude. Specifically we present an analytic form for the single trace $N_c$ independent colour partial amplitude for the case where all external…

High Energy Physics - Phenomenology · Physics 2020-04-08 David C. Dunbar , Warren B. Perkins , Joseph M. W. Strong

We compute three-loop QCD corrections to the scattering amplitude of a Higgs boson and three partons interfered with its tree level counterpart. Specifically, we derive our results in the generalized leading color limit. Our results are…

High Energy Physics - Phenomenology · Physics 2025-04-10 Xiang Chen , Xin Guan , Bernhard Mistlberger

Recently, the spinor helicity formalism and on-shell superspace were developed for six-dimensional gauge theories with (1,1) supersymmetry. We combine these two techniques with (generalised) unitarity, which is a powerful technique to…

High Energy Physics - Theory · Physics 2011-03-02 Andreas Brandhuber , Dimitrios Korres , Daniel Koschade , Gabriele Travaglini

We consider the singular behaviour of one-loop QCD matrix elements when several external partons become simultaneously parallel. We present a new factorization formula that describes the singular collinear behaviour directly in colour…

High Energy Physics - Phenomenology · Physics 2010-04-05 Stefano Catani , Daniel de Florian , German Rodrigo

We present a technique which utilizes unitarity and collinear limits to construct ansatze for one-loop amplitudes in gauge theory. As an example, we obtain the one-loop contribution to amplitudes for $n$ gluon scattering in $N=4$…

High Energy Physics - Phenomenology · Physics 2009-09-25 Z. Bern , L. Dixon , D. C. Dunbar , D. A. Kosower

We briefly describe a new general algorithm for carrying out QCD calculations to next-to-leading order in perturbation theory. The algorithm can be used for computing arbitrary jet cross sections in arbitrary processes and can be…

High Energy Physics - Phenomenology · Physics 2015-06-25 Stefano Catani , Michael H. Seymour

We present a subtraction method utilizing the N-jettiness observable, Tau_N, to perform QCD calculations for arbitrary processes at next-to-next-to-leading order (NNLO). Our method employs soft-collinear effective theory (SCET) to determine…

High Energy Physics - Phenomenology · Physics 2015-09-29 Jonathan Gaunt , Maximilian Stahlhofen , Frank J. Tackmann , Jonathan R. Walsh

We study the application of recursion relations to the calculation of finite one-loop gravity amplitudes. It is shown explicitly that the known four, five, and six graviton one-loop amplitudes for which the external legs have identical…

High Energy Physics - Theory · Physics 2010-10-27 Andreas Brandhuber , Simon McNamara , Bill Spence , Gabriele Travaglini

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 describe a new method for the automated construction of one-loop amplitudes based on the open-loop algorithm, where various operations are performed on-the-fly while constructing the integrand. In particular, an on-the-fly reduction…

High Energy Physics - Phenomenology · Physics 2018-01-12 Federico Buccioni , Stefano Pozzorini , Max Zoller

Knowledge of two-loop QCD amplitudes for processes $q\bar q \to V_1 V_2 \to (l_1\bar l'_1)(l_2 \bar l'_2)$ is important for improving the theoretical description of four-lepton production in hadron collisions. In this paper we compute these…

High Energy Physics - Phenomenology · Physics 2015-06-22 Fabrizio Caola , Johannes M. Henn , Kirill Melnikov , Alexander V. Smirnov , Vladimir A. Smirnov

Some of the tools and techniques that have recently been used to compute Higgs boson pair production at NLO in QCD are discussed. The calculation relies on the use of integral reduction, to reduce the number of integrals which must be…

High Energy Physics - Phenomenology · Physics 2016-08-15 S. P. Jones

We derive the two-loop QCD helicity amplitudes for the processes $l q \to l qg$ ($l \bar q \to l \bar q g$) and $l g \to l q\bar q$, which are the partonic reactions yielding $(2+1)$-jet final states in deep inelastic lepton nucleon…

High Energy Physics - Phenomenology · Physics 2009-06-25 T. Gehrmann , E. W. N. Glover

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

We compute the next-to-leading order QCD corrections to the spin-independent and spin-dependent cross-sections for the production of a single-hadron accompanied by an opposite jet in hadronic collisions. This process is being studied…

High Energy Physics - Phenomenology · Physics 2009-07-30 Daniel de Florian

We compute the leading color, next-to-leading order QCD corrections to the dominant partonic channels for the production of a W boson in association with three jets at the Tevatron and the LHC. This is the first application of generalized…

High Energy Physics - Phenomenology · Physics 2010-01-07 R. Keith Ellis , Kirill Melnikov , Giulia Zanderighi

We discuss how the multi-Regge factorisation of QCD amplitudes can be used in the study of multi-jet processes at colliders. We describe how the next-to-leading logarithmic (NLL) BFKL evolution can be combined with energy and momentum…

High Energy Physics - Phenomenology · Physics 2017-08-23 Jeppe R. Andersen

We present the computation of next-to-leading order (NLO) QCD corrections to di-photon production in association with two or three hard jets in pp collisions at a center-of-mass energy of 8 TeV. The inclusion of NLO corrections is shown to…

High Energy Physics - Phenomenology · Physics 2015-06-18 Simon Badger , Alberto Guffanti , Valery Yundin