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Related papers: Scattering Amplitudes with Open Loops

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We present a method for the computation of hepta-cuts of two loop scattering amplitudes. Four dimensional unitarity cuts are used to factorise the integrand onto the product of six tree-level amplitudes evaluated at complex momentum values.…

High Energy Physics - Phenomenology · Physics 2012-04-18 Simon Badger , Hjalte Frellesvig , Yang Zhang

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

We review some of the modern approaches to scattering amplitude computations in QCD and their application to precision LHC phenomenology. We emphasise the usefulness of momentum twistor variables in parameterising general amplitudes.

High Energy Physics - Phenomenology · Physics 2016-12-21 Simon Badger

We initiate the study of positive geometry and scattering forms for tree-level amplitudes with matter particles in the (anti-)fundamental representation of the color/flavor group. As a toy example, we study the bi-color scalar theory, which…

High Energy Physics - Theory · Physics 2020-06-08 Aidan Herderschee , Song He , Fei Teng , Yong Zhang

These notes are a written version of my talk given at the CARMA workshop in June 2017, with some additional material. I presented a few concepts that have recently been used in the computation of tree-level scattering amplitudes (mostly…

Combinatorics · Mathematics 2020-12-01 Carlos R. Mafra

We propose a method to compute the scattering angle for classical black hole scattering directly from two massive particle irreducible diagrams in a heavy-mass effective field theory approach to general relativity, without the need of…

High Energy Physics - Theory · Physics 2021-11-03 Andreas Brandhuber , Gang Chen , Gabriele Travaglini , Congkao Wen

Multi-loop scattering amplitudes constitute a serious bottleneck in current high-energy physics computations. Obtaining new integrand level representations with smooth behaviour is crucial for solving this issue, and surpassing the…

High Energy Physics - Phenomenology · Physics 2021-09-17 German F. R. Sborlini

A fraction of a laser beam array, whose unknown phase relationships must be set to prescribed values, is launched into a scattering media with random transmission. The resulting output speckle pattern is sampled by an array of photodiodes…

Gauge theory amplitudes in a non-helicity format are generated at all $n$-point and at tree level. These amplitudes inherit structure from $\phi^3$ classical scattering, and the string inspired formalism is used to find the tensor algebra.…

General Physics · Physics 2007-05-23 Gordon Chalmers

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

We introduce a formalism for describing four-dimensional scattering amplitudes for particles of any mass and spin. This naturally extends the familiar spinor-helicity formalism for massless particles to one where these variables carry an…

High Energy Physics - Theory · Physics 2021-11-02 Nima Arkani-Hamed , Tzu-Chen Huang , Yu-tin Huang

We present recent advancements in the computation of three-loop four-particle helicity amplitudes in full-color massless QCD. In this contribution, we focus on the $gg \to \gamma\gamma$ process. We show how to obtain compact analytic…

High Energy Physics - Phenomenology · Physics 2024-10-04 Piotr Bargiela

The fundamental quantities of potential scattering theory are generalized to accommodate long-range interactions. New definitions for the scattering amplitude and wave operators valid for arbitrary interactions including potentials with a…

Nuclear Theory · Physics 2009-02-05 A. S. Kadyrov , I. Bray , A. M. Mukhamedzhanov , A. T. Stelbovics

We present a new approach to the reduction of one-loop amplitudes obtained by reconstructing the tensorial expression of the scattering amplitudes. The reconstruction is performed at the integrand level by means of a sampling in the…

High Energy Physics - Phenomenology · Physics 2010-11-08 G. Heinrich , G. Ossola , T. Reiter , F. Tramontano

The twistor diagram formalism for scattering amplitudes is introduced, emphasising its finiteness and conformal symmetry. It is shown how MHV amplitudes are simply represented by twistor diagrams. Then the Britto-Cachazo-Feng recursion…

High Energy Physics - Theory · Physics 2007-05-23 Andrew Hodges

The standard unitarity-cut method is applied to several massive two-dimensional models, including the world-sheet AdS$_5\times S^5$ superstring, to compute $2\to 2$ scattering S-matrices at one loop from tree level amplitudes. Evidence is…

High Energy Physics - Theory · Physics 2014-01-03 Valentina Forini , Lorenzo Bianchi , Ben Hoare

We connect quantum compact graphs with infinite leads, and turn them into scattering systems. We derive an exact expression for the scattering matrix, and explain how it is related to the spectrum of the corresponding closed graph. The…

Chaotic Dynamics · Physics 2007-05-23 Tsampikos Kottos , Holger Schanz

We compute the simplest one-loop planar amplitudes in Higgsed ABJM theory at a generic point of the moduli space. We explicitly check that they can be expressed in terms of integrals which are invariant under dual conformal symmetry…

High Energy Physics - Theory · Physics 2015-11-05 Marco S. Bianchi

We describe the unitarity approach for the numerical computation of two-loop integral coefficients of scattering amplitudes. It is well known that the leading propagator singularities of an amplitude's integrand are related to products of…

High Energy Physics - Phenomenology · Physics 2017-06-07 S. Abreu , F. Febres Cordero , H. Ita , M. Jaquier , B. Page

Amplitude methods have proven to be a promising technique to perform Post-Minkowskian calculations used as inputs to construct gravitational waveforms. In this paper, we show how these methods can be extended beyond the standard…

High Energy Physics - Theory · Physics 2022-06-28 Mariana Carrillo-González , Claudia de Rham , Andrew J. Tolley