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Related papers: Multi-Parton Scattering Amplitudes via On-Shell Me…

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We consider the factorization properties of on-shell QCD amplitudes with massive partons in the limit when all kinematical invariants are large compared to the parton mass and discuss the structure of their infrared singularities. The…

High Energy Physics - Phenomenology · Physics 2009-01-07 S. Moch , A. Mitov

We compute the two-loop QED helicity amplitudes for the scattering of a lepton pair with an off-shell and an on-shell photon, $0\to\ell\bar\ell\gamma\gamma^*$, using the approximation of massless leptons. We express all master integrals…

High Energy Physics - Phenomenology · Physics 2023-11-10 Simon Badger , Jakub Kryś , Ryan Moodie , Simone Zoia

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 present an alternative method to calculate cross sections for multi-parton scattering processes in the Standard Model at leading order. The helicity amplitudes are computed using recursion relations in the number of particles, based on…

High Energy Physics - Phenomenology · Physics 2008-11-26 Costas G. Papadopoulos , Malgorzata Worek

We demonstrate that the use of on-shell methods involving calculation of the discontinuity across the t-channel cut associated with the exchange of a pair of massless particles can be used to evaluate loop contributions to the…

High Energy Physics - Phenomenology · Physics 2016-11-10 Barry R. Holstein

We review recent progress on the calculation of scattering amplitudes in the high-energy limit. We start by illustrating the shockwave formalism, which allows one to calculate amplitudes as iterated solutions of rapidity evolution…

High Energy Physics - Phenomenology · Physics 2021-11-10 Leonardo Vernazza , Giulio Falcioni , Einan Gardi , Niamh Maher , Calum Milloy

Several methods of extracting the magnitude of the real parts of the elastic hadron scattering amplitude - from the experimental data are presented. These methods allows us to obtain the real parts at one definite point of the transfer…

High Energy Physics - Phenomenology · Physics 2007-05-23 O. V. Selyugin

We investigate several ingredients for a theory of multiple hard scattering in hadron-hadron collisions. Issues discussed include the space-time structure of multiple interactions, their power behavior, spin and color correlations,…

High Energy Physics - Phenomenology · Physics 2011-04-20 Markus Diehl , Andreas Schafer

The consistent construction of scattering amplitudes for processes with off-shell initial partons and involving electro-weak interactions is addressed.

High Energy Physics - Phenomenology · Physics 2019-02-06 A. van Hameren

The study of long-range effects arising from the higher order exchange of massless particles via summation of Feynman diagrams is well known, but recently it has been shown that the use of on-shell methods can provide a streamlined route to…

Nuclear Theory · Physics 2023-07-26 Barry R. Holstein

We compute all helicity amplitudes for the scattering of five partons in two-loop QCD in all the relevant flavor configurations, retaining all contributing color structures. We employ tensor projection to obtain helicity amplitudes in the…

High Energy Physics - Phenomenology · Physics 2023-12-01 Bakul Agarwal , Federico Buccioni , Federica Devoto , Giulio Gambuti , Andreas von Manteuffel , Lorenzo Tancredi

We establish an efficient polynomial-complexity algorithm for one-loop calculations, based on generalized $D$-dimensional unitarity. It allows automated computations of both cut-constructible {\it and} rational parts of one-loop scattering…

High Energy Physics - Phenomenology · Physics 2009-09-17 Walter T. Giele , Zoltan Kunszt , Kirill Melnikov

A prescription is presented to construct manifestly gauge invariant tree-level scattering amplitudes with one or two off-shell initial-state gluons for processes with arbitrary particles in the final state, which allows for calculations…

High Energy Physics - Phenomenology · Physics 2013-07-09 A. van Hameren

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 present a formalism for computing classically measurable quantities directly from on-shell quantum scattering amplitudes. We discuss the ingredients needed for obtaining the classical result, and show how to set up the calculation to…

High Energy Physics - Theory · Physics 2019-03-27 David A. Kosower , Ben Maybee , Donal O'Connell

We recently presented a new method for the evaluation of one-loop amplitude of arbitrary scattering processes, in which the reduction to scalar integrals is performed at the integrand level. In this talk, we review the main features of the…

High Energy Physics - Phenomenology · Physics 2007-09-17 Giovanni Ossola

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 perform a detailed investigation of multiple hard interactions in hadron-hadron collisions. We discuss the space-time, spin and color structure of multiple interactions, classify different contributions according to their power behavior…

High Energy Physics - Phenomenology · Physics 2016-02-19 Markus Diehl , Daniel Ostermeier , Andreas Schafer

We review some of the recent advances in the computation of one-loop scattering amplitudes which led to the construction of efficient and automated computational tools for NLO predictions. Particular attention is devoted to unitarity-based…

High Energy Physics - Phenomenology · Physics 2015-06-17 Giovanni Ossola

We review on-shell and unitarity methods and discuss their application to precision predictions for LHC physics. Being universal and numerically robust, these methods are straight-forward to automate for next-to-leading-order computations…

High Energy Physics - Theory · Physics 2015-05-30 Harald Ita