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Related papers: Ordering multiple soft gluon emissions

200 papers

We review techniques simplifying the analytic calculation of one-loop QCD amplitudes with many external legs, for use in next-to-leading-order corrections to multi-jet processes. We explain how a supersymmetry-inspired organization works…

High Energy Physics - Phenomenology · Physics 2007-05-23 L. Dixon

We present advances in the development of the numerical unitarity method for the computation of multi-loop amplitudes in QCD. As an application, we show results for all the leading-color two-loop five-gluon helicity amplitudes. The…

High Energy Physics - Phenomenology · Physics 2018-07-26 Samuel Abreu , Fernando Febres Cordero , Harald Ita , Ben Page , Mao Zeng

We derive an all order resummation formula for the deeply virtual Compton scattering (DVCS) amplitude, which takes into account soft gluon exchanges in the non-singlet quark coefficient function. We identify the ladder diagrams responsible…

High Energy Physics - Phenomenology · Physics 2012-06-18 T. Altinoluk , B. Pire , L. Szymanowski , S. Wallon

The high energy amplitudes of the large angles Moller scattering are calculated in frame of chiral basis in Born and 1-loop QED level. Taking into account as well the contribution from emission of soft real photons the compact relations…

High Energy Physics - Phenomenology · Physics 2015-06-03 A. I. Ahmadov , Yu. M. Bystritskiy , A. N. Ilyichev , E. A. Kuraev , V. A. Zykunov

We compute the full-color two-loop five-gluon amplitude for the all-plus helicity configuration. In order to achieve this, we calculate the required master integrals for all permutations of the external legs, in the physical scattering…

High Energy Physics - Phenomenology · Physics 2019-08-21 S. Badger , D. Chicherin , T. Gehrmann , G. Heinrich , J. M. Henn , T. Peraro , P. Wasser , Y. Zhang , S. Zoia

We present an efficient way to calculate the effect of soft QCD radiation at one loop, which is needed for predictions at next-to-next-to-leading logarithmic accuracy. We use rapidity coordinates and isolate the divergences in the…

High Energy Physics - Phenomenology · Physics 2016-04-20 Tomas Kasemets , Wouter J. Waalewijn , Lisa Zeune

We present a calculation of the helicity amplitudes for the process $gg\to\gamma\gamma$ in three-loop massless QCD. We employ a recently proposed method to calculate scattering amplitudes in the 't Hooft-Veltman scheme that reduces the…

High Energy Physics - Phenomenology · Physics 2022-04-05 Piotr Bargiela , Fabrizio Caola , Andreas von Manteuffel , Lorenzo Tancredi

We present a computer library for the numerical evaluation of colour-ordered n-gluon amplitudes at one-loop order in pure Yang-Mills theory. The library uses the recently developed technique of generalised unitarity. Running in double…

High Energy Physics - Phenomenology · Physics 2013-03-05 Simon Badger , Benedikt Biedermann , Peter Uwer

The efficient computation of color-summed QCD amplitudes at high parton multiplicities remains a central challenge for precision collider predictions. Existing approaches using trace, color-flow, or adjoint bases suffer from…

High Energy Physics - Phenomenology · Physics 2025-07-31 Oskar Bolinder , Rikkert Frederix , Malin Sjodahl

We compute the leading colour contributions to five-gluon scattering at two loops in massless QCD. The integrands of all independent helicity amplitudes are evaluated using d-dimensional generalised unitarity cuts and finite field…

High Energy Physics - Phenomenology · Physics 2018-03-07 Simon Badger , Christian Brønnum-Hansen , Heribertus Bayu Hartanto , Tiziano Peraro

We introduce a new technique to generate scattering amplitudes at one loop. Traditional tree algorithms, which handle diagrams with fixed momenta, are promoted to generators of loop-momentum polynomials that we call open loops. Combining…

High Energy Physics - Phenomenology · Physics 2013-05-30 Fabio Cascioli , Philipp Maierhöfer , Stefano Pozzorini

General equations for the calculation of amplitudes are presented. As an illustration of application of proposed formulae we calculate electron-electron scattering amplitudes.

High Energy Physics - Phenomenology · Physics 2007-05-23 Alexander L. Bondarev

We discuss the QED-generalized leading-twist light-cone distribution amplitudes of heavy mesons, that appear in QCD$\times$QED factorization theorems for exclusive two-body $B$ decays. In the presence of electrically charged particles,…

High Energy Physics - Phenomenology · Physics 2022-08-24 Martin Beneke , Philipp Böer , Jan-Niklas Toelstede , Keri K. Vos

We study two-to-two parton scattering amplitudes in the high-energy limit of perturbative QCD by iteratively solving the BFKL equation. This allows us to predict the imaginary part of the amplitude to leading-logarithmic order for arbitrary…

High Energy Physics - Phenomenology · Physics 2020-06-03 Simon Caron-Huot , Einan Gardi , Joscha Reichel , Leonardo Vernazza

We apply the Low's theorem to soft gluon emission from heavy quark scattering in the nonperturbative strongly interacting quark-gluon plasma (sQGP). The sQGP is described in terms of the dynamical quasi-particles and adjusted to reproduce…

Nuclear Theory · Physics 2023-02-22 Taesoo Song , Ilia Grishmanovskii , Olga Soloveva

We present a much simpler analytic expression for the UV un-renormalized one-loop soft-gluon current which controls the infra-red behavior of one-loop QCD amplitudes with massive fermions when an external gluon becomes soft. The result is…

High Energy Physics - Phenomenology · Physics 2018-04-09 Michal Czakon , Alexander Mitov

We review recent progress in determining the infrared singularity structure of on-shell scattering amplitudes in massless gauge theories. We present a simple ansatz where soft singularities of any scattering amplitude of massless partons,…

High Energy Physics - Phenomenology · Physics 2014-11-20 Einan Gardi , Lorenzo Magnea

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 propose to make use of the off-shell recursive relations with the color-flow decomposition in the calculation of QCD amplitudes on MadGraph. We introduce colored quarks and their interactions with nine gluons in the color-flow basis plus…

High Energy Physics - Phenomenology · Physics 2011-06-08 Kaoru Hagiwara , Yoshitaro Takaesu

We present the two-loop helicity amplitudes for the scattering of massless quarks and massless gauge bosons in QCD. We use projector techniques to compute the coefficients of the general tensor describing the two-quark two-boson amplitude…

High Energy Physics - Phenomenology · Physics 2010-02-03 E. W. N. Glover , M. E. Tejeda-Yeomans