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Related papers: One-Loop Amplitudes for e^+ e^- to Four Partons

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The production of massive quarks and leptons in $e^+e^-$ collisions is studied using exact helicity amplitudes. Total cross sections as a function of $y_{\rm cut}$, in both the JADE and the $k_T$ algorithms, are presented and compared with…

High Energy Physics - Phenomenology · Physics 2009-10-22 A. Ballestrero , E. Maina , S. Moretti

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 describe a general method that enables us to obtain all the singular terms of helicity amplitudes of n-parton processes at one loop. The algorithm uses helicity amplitudes at tree level and simple color algebra. We illustrate the method…

High Energy Physics - Phenomenology · Physics 2009-10-28 Zoltan Kunszt , Adrian Signer , Zoltan Trocsanyi

In this addendum to our paper entitled "W^+- H^-+ Associated Production at the Large Hadron Collider" [Phys. Rev. D 59, 015009 (1999)], we list analytic results for the helicity amplitudes of the partonic subprocess gg -> W^-H^+ induced by…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. A. Barrientos Bendezu , B. A. Kniehl

We calculate the one-loop electroweak corrections to e+e- to WWZ and e+e- to ZZZ and analyse their impacts on both the total cross section and some key distributions. These processes are important for the measurements of the quartic…

High Energy Physics - Phenomenology · Physics 2010-04-27 Fawzi Boudjema , Le Duc Ninh , Sun Hao , Marcus M. Weber

We compute the complete one-loop corrections to the simplest class of QCD gluon amplitudes, those with two color-adjacent opposite-helicity external particles. We present results for an arbitrary number of external legs. The computation…

High Energy Physics - Phenomenology · Physics 2009-11-11 Darren Forde , David A. Kosower

We compute the two-loop corrections to the helicity amplitudes for the coupling of a massive vector boson to a massless quark-antiquark pair and a gluon, accounting for vector and axial-vector couplings of the vector boson and…

High Energy Physics - Phenomenology · Physics 2023-06-19 Thomas Gehrmann , Tiziano Peraro , Lorenzo Tancredi

The evolution equation for parton multiplicities in quark and gluon jets which takes into account the soft gluon interference is solved numerically using the initial conditions at threshold. If the k_T-cutoff Q_c is lowered towards the…

High Energy Physics - Phenomenology · Physics 2009-10-30 Sergio Lupia , Wolfgang Ochs

Results for higher-order threshold enhancements in high-E_T jet production in hadron-hadron collisions are presented. Expressions are given for the next-to-next-to-leading order (NNLO) threshold corrections to the single-jet inclusive cross…

High Energy Physics - Phenomenology · Physics 2009-10-31 Nikolaos Kidonakis , J. F. Owens

We re-compute the recently derived two-loop five-point all plus Yang-Mills amplitude using Unitarity and Recursion. Recursion requires augmented recursion to determine the sub-leading pole. Using these methods the simplicity of this…

High Energy Physics - Theory · Physics 2016-04-27 David C. Dunbar , Warren B. Perkins

We present the two-loop QCD helicity amplitudes for quark-quark and quark-antiquark scattering. These amplitudes are relevant for next-to-next-to-leading order corrections to (polarized) jet production at hadron colliders. We give the…

High Energy Physics - Phenomenology · Physics 2014-01-27 Abilio De Freitas , Zvi Bern

This paper presents the high-precision theoretical predictions for $e^+e^- \to l^-l^+$ scattering. Calculations are performed using the {\tt SANC} system. They take into account complete one-loop electroweak radiative corrections as well as…

High Energy Physics - Phenomenology · Physics 2020-09-02 S. Bondarenko , Ya. Dydyshka , L. Kalinovskaya , R. Sadykov , V. Yermolchyk

We present an enumeration of all possible amplitudes that contribute to an n-jet process in QCD. We estimate the number of amplitudes for large number of jets and determine the actual number of amplitudes to be calculated, which is smaller…

High Energy Physics - Phenomenology · Physics 2011-09-13 Petros D. Draggiotis , Ronald Kleiss

For the case of $n$-jet production at next-to-next-to-leading order in the QCD coupling, in the infrared divergent corners of phase space where particles are collinear or soft, one must evaluate $(n+1)$-parton final-state one-loop…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zvi Bern , Vittorio Del Duca , Carl R. Schmidt

We present a fully analytic calculation of the leading-order one-loop amplitude for triple Higgs production via gluon fusion, $gg \to HHH$, retaining full dependence on the mass of the heavy quark circulating in the loop. This amplitude…

High Energy Physics - Phenomenology · Physics 2025-07-28 John M. Campbell , Giuseppe De Laurentis , R. Keith Ellis

Recently the calculations of all five-parton one-loop QCD amplitudes have been completed. In this letter we describe how to get the corresponding amplitudes with one gluon replaced by a photon and we give the explicit results for the…

High Energy Physics - Phenomenology · Physics 2009-10-28 Adrian Signer

We consider a Higgs boson coupled to gluons via the five-dimensional effective operator H tr G_{\mu\nu}G^{\mu\nu}. We treat H as the real part of a complex field phi that couples to the selfdual gluon field strengths and compute the…

High Energy Physics - Phenomenology · Physics 2009-02-09 E. W. N. Glover , Pierpaolo Mastrolia , Ciaran Williams

In this paper we discuss in detail computational methods and new results for one-loop virtual corrections to N = 4 super Yang-Mills scattering amplitudes calculated to all orders in epsilon, the dimensional regularization parameter. It is…

High Energy Physics - Theory · Physics 2015-03-19 Robert M. Schabinger

We calculate the complete set of two-loop leading-colour QCD helicity amplitudes for $\gamma \gamma j$-production at hadron colliders. Our results are presented in a compact, fully-analytical form.

High Energy Physics - Phenomenology · Physics 2021-08-25 Herschel A. Chawdhry , Michal Czakon , Alexander Mitov , Rene Poncelet

We compute the one-loop QCD amplitude for the process gg-->Q\bar{Q} in dimensional regularization through order \epsilon^2 in the dimensional regulator and for arbitrary quark mass values. This result is an ingredient of the NNLO…

High Energy Physics - Phenomenology · Physics 2008-12-30 Charalampos Anastasiou , S. Mert Aybat