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Related papers: Very Compact Expressions for Amplitudes

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The formal properties of the recently derived set of linearly independent invariant amplitudes for the electromagnetic production of a pseudoscalar particle from a spin-one particle have been further exploited. The crossing properties are…

Nuclear Theory · Physics 2009-10-31 Hartmuth Arenhoevel

The seven-gluon two-loop full-color Yang-Mills amplitude is presented in a compact analytic form where we use the methods of four-dimensional unitarity cuts to obtain the polylogarithmic pieces and augmented recursion to obtain the rational…

High Energy Physics - Phenomenology · Physics 2025-01-14 Adam R. Dalgleish , David C. Dunbar , Warren B. Perkins , Joseph M. W. Strong

Loop amplitudes are conveniently expressed in terms of master integrals whose coefficients carry the process dependent information. Similarly before integration, the loop integrands may be expressed as a linear combination of propagator…

High Energy Physics - Theory · Physics 2016-12-28 Harald Ita

A new algorithm to calculate Coulomb wave functions with all of its arguments complex is proposed. For that purpose, standard methods such as continued fractions and power/asymptotic series are combined with direct integrations of the…

Computational Physics · Physics 2009-11-13 N. Michel

Multi-loop interaction amplitudes in the theory of the closed, oriented superstrings are obtained by the integration of local amplitudes which are represented by a sum of the spinning string local amplitudes. The last local amplitudes are…

High Energy Physics - Theory · Physics 2016-11-15 G. S. Danilov

In this paper, we propose a method to construct the decay amplitudes in the orbital ($L$) and spin ($S$) coupling scheme for particles with arbitrary spins. For the $1\to 2$ decay with only massive particles involved, the angular dependence…

High Energy Physics - Phenomenology · Physics 2023-09-14 Xiao-yu Li , Xiang-Kun Dong , Hao-Jie Jing

We propose an all-loop expression for scattering amplitudes in planar N=4 super Yang-Mills theory in multi-Regge kinematics valid for all multiplicities, all helicity configurations and arbitrary logarithmic accuracy. Our expression is…

High Energy Physics - Theory · Physics 2020-12-16 V. Del Duca , S. Druc , J. M. Drummond , C. Duhr , F. Dulat , R. Marzucca , G. Papathanasiou , B. Verbeek

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 propose a first implementation of the integrand-reduction method for two-loop scattering amplitudes. We show that the residues of the amplitudes on multi-particle cuts are polynomials in the irreducible scalar products involving the loop…

High Energy Physics - Phenomenology · Physics 2015-05-30 Pierpaolo Mastrolia , Giovanni Ossola

We explain how one-loop amplitudes with massive fermions can be computed using only on-shell information. We first use the spinor-helicity formalism in six dimensions to perform generalised unitarity cuts in $d$ dimensions. We then show…

High Energy Physics - Phenomenology · Physics 2017-08-02 Simon Badger , Christian Brønnum-Hansen , Francesco Buciuni , Donal O'Connell

Tree-level amplitudes of gauge theories are expressed in a basis of auxiliary amplitudes with only cubic vertices. The vertices in this formalism are explicitly factorized in color and kinematics, clarifying the color-kinematics duality in…

High Energy Physics - Theory · Physics 2015-06-04 N. E. J. Bjerrum-Bohr , Poul H. Damgaard , Ricardo Monteiro , Donal O'Connell

All four-point mixed gluon-graviton amplitudes in pure Einstein-Yang-Mills theory with at most one state of negative helicity are computed at one-loop order and maximal powers of the gauge coupling using D-dimensional generalized unitarity.…

High Energy Physics - Theory · Physics 2018-09-26 Dhritiman Nandan , Jan Plefka , Gabriele Travaglini

Multiloop scattering amplitudes describing the quantum fluctuations at high-energy scattering processes are the main bottleneck in perturbative quantum field theory. The loop-tree duality is a novel method aimed at overcoming this…

We present a quantum algorithm for the calculation of scattering amplitudes of massive charged scalar particles in scalar quantum electrodynamics. Our algorithm is based on continuous-variable quantum computing architecture resulting in…

Quantum Physics · Physics 2018-02-21 Kübra Yeter-Aydeniz , George Siopsis

We derive a general formalism that relates the spectrum of two-particle systems in a finite volume to physical scattering amplitudes, taking into account the presence of any left-hand branch cuts due to single-particle exchanges. The method…

High Energy Physics - Lattice · Physics 2025-02-27 André Baião Raposo , Raúl A Briceño , Maxwell T Hansen , Andrew W Jackura

This article reviews recent progress in formulating double-copy constructions for scattering amplitudes in supergravity theories with N=2 supersymmetry in five and four spacetime dimensions. Particular attention is devoted to infinite…

High Energy Physics - Theory · Physics 2016-07-15 Marco Chiodaroli

In this talk we present techniques for calculating one-loop amplitudes for multi-leg processes using Feynman diagrammatic methods in a semi-algebraic context. Our approach combines the advantages of the different methods allowing for a fast…

We expose simple and practical relations between the integrated four- and five-point one-loop amplitudes of N >= 4 supergravity and the corresponding (super-)Yang-Mills amplitudes. The link between the amplitudes is simply understood using…

High Energy Physics - Theory · Physics 2013-05-29 Z. Bern , C. Boucher-Veronneau , H. Johansson

We develop a unitarity method to compute one-loop amplitudes with massless propagators in d=4-2*epsilon dimensions. We compute double cuts of the loop amplitudes via a decomposition into a four-dimensional and a -2*epsilon-dimensional…

High Energy Physics - Phenomenology · Physics 2008-11-26 Charalampos Anastasiou , Ruth Britto , Bo Feng , Zoltan Kunszt , Pierpaolo Mastrolia

Using an iterative solution of rapidity evolution equations, we compute partonic $2\to 2$ gauge theory amplitudes at four loops in full colour up to the Next-to-Next-to-Leading Logarithms (NNLL) in the Regge limit. By contrasting the…

High Energy Physics - Phenomenology · Physics 2021-09-08 Giulio Falcioni , Einan Gardi , Calum Milloy , Leonardo Vernazza