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Related papers: Calculating Scattering Amplitudes Efficiently

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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

A central problem in quantum field theory is the computation of scattering amplitudes. However, traditional methods are impractical to calculate high order phenomenologically relevant observables. Building on a few decades of astonishing…

High Energy Physics - Theory · Physics 2017-06-28 Livia Ferro , Tomasz Lukowski , Andrea Orta , Matteo Parisi

We apply the solution to the recursion relation for the double-off-shell quark current to the problem of computing one loop amplitudes with an arbitrary number of gluons. We are able to compute amplitudes for photon-gluon scattering,…

High Energy Physics - Phenomenology · Physics 2009-10-22 Gregory Mahlon

We derive general tree-level recursion relations for amplitudes which include massive propagating particles. As an illustration, we apply these recursion relations to scattering amplitudes of gluons coupled to massive scalars. We provide…

High Energy Physics - Theory · Physics 2009-11-11 S. D. Badger , E. W. N. Glover , V. V. Khoze , P. Svrcek

We present a new method for computing multi-loop scattering amplitudes in Quantum Field Theory. It extends the Generalized Unitarity method by constraining not only the integrand of the amplitude but also its full integrated form. Our…

High Energy Physics - Theory · Physics 2025-12-18 Piotr Bargiela

We present on the use of on-shell recursion relations. These can be used not only for calculating tree amplitudes, including those with masses, but also to compute analytically the missing rational terms of one-loop QCD amplitudes. Combined…

High Energy Physics - Phenomenology · Physics 2017-08-23 Darren Forde

We review on the recent developments for the computation of scattering amplitudes, with attention to the on-shell formalisms and unitarity-based methods.

High Energy Physics - Phenomenology · Physics 2007-05-23 Pierpaolo Mastrolia

A new method of calculation of amplitudes of different processes in quantum electrodynamics is proposed. The method does not use the Feynman technique of trace of product of matrices calculation. The method strongly simplifies calculation…

High Energy Physics - Phenomenology · Physics 2015-06-05 Kostyantyn Karplyuk , Oleksandr Zhmudsky

We present the first public version of Caravel, a C++17 framework for the computation of multi-loop scattering amplitudes in quantum field theory, based on the numerical unitarity method. Caravel is composed of modules for the…

High Energy Physics - Phenomenology · Physics 2021-07-28 S. Abreu , J. Dormans , F. Febres Cordero , H. Ita , M. Kraus , B. Page , E. Pascual , M. S. Ruf , V. Sotnikov

In the framework of a toy model which possesses the main features of QCD in the high energy limit, we conduct a numerical study of scattering amplitudes constructed from parton splittings and projectile-target multiple interactions, in a…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Munier , F. Schwennsen

We explore how various topics in modern scattering amplitudes research find application in the description of collider physics processes. After a brief review of experimentally measured quantities and how they are related to amplitudes, we…

High Energy Physics - Theory · Physics 2023-01-10 Chris D. White

We calculate two-body scattering phase shifts on a quantum computer using a leading order short-range effective field theory Hamiltonian. The algorithm combines the variational quantum eigensolver and the quantum subspace expansion. As an…

Nuclear Theory · Physics 2024-11-21 Sanket Sharma , Thomas Papenbrock , Lucas Platter

We study the QCD scattering amplitudes for \bar{q}q \to gg and \bar{q}q \to ggg where q is a massive fermion. Using a particular choice of massive fermion spinor we are able to derive very compact expressions for the partial spin amplitudes…

High Energy Physics - Phenomenology · Physics 2009-01-07 K. J. Ozeren , W. J. Stirling

We present analytical results for all six-photon helicity amplitudes. For the computation of this loop induced process two recently developed methods, based on form factor decomposition and on multiple cuts, have been used. We obtain…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. Binoth , T. Gehrmann , G. Heinrich , P. Mastrolia

We present the analytic form of the two-loop five-gluon scattering amplitudes in QCD for a complete set of independent helicity configurations of external gluons. These include the first analytic results for five-point two-loop amplitudes…

High Energy Physics - Phenomenology · Physics 2019-03-06 S. Abreu , J. Dormans , F. Febres Cordero , H. Ita , B. Page

In this paper, we present an improvement of a method for computing scattering amplitudes that include external (polarized) fermions with the following features: the formulas are quite general and work for different kinematic configurations…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. Chopin

These lectures are centred around tree-level scattering amplitudes in pure Yang-Mills theories, the most prominent example is given by the tree-level gluon amplitudes of QCD. I will discuss several ways of computing these amplitudes,…

High Energy Physics - Theory · Physics 2017-01-23 Stefan Weinzierl

We compute meson scattering amplitudes using the holographic duality between confining gauge theories and string theory, in order to consider holographic corrections to the Veneziano amplitude and associated higher-point functions. The…

High Energy Physics - Theory · Physics 2017-04-26 Adi Armoni , Edwin Ireson

We present a method for the direct extraction of rational contributions to one-loop scattering amplitudes, missed by standard four-dimensional unitarity techniques. We use generalised unitarity in $D=4-2\e$ dimensions to write the loop…

High Energy Physics - Phenomenology · Physics 2009-01-27 S. D. Badger