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Related papers: On the interplay between the loop-tree duality and…

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We present the first numerical computation of two-loop amplitudes based on the unitarity method. As a proof of principle, we compute the four-gluon process. We discuss the new method, analyze its numerical properties and apply it to…

High Energy Physics - Phenomenology · Physics 2017-10-11 S. Abreu , F. Febres Cordero , H. Ita , M. Jaquier , B. Page , M. Zeng

We present the analytic expressions of the three-loop virtual corrections to the helicity amplitudes of 2 -> 2 four-fermion scattering processes in massless QED. The contributing Feynman diagrams are grouped into integrand families…

High Energy Physics - Phenomenology · Physics 2026-02-12 Giulio Crisanti , Thomas Dave , Pierpaolo Mastrolia , Jonathan Ronca , Sid Smith , William J. Torres Bobadilla

We calculate the genus-one three- and four-point amplitudes in the 2+2 dimensional closed N=(2,2) worldsheet supersymmetric string within the RNS formulation. Vertex operators are redefined with the incorporation of spinor helicity…

High Energy Physics - Theory · Physics 2009-10-31 Gordon Chalmers , Olaf Lechtenfeld , Bernd Niemeyer

A proof-of-concept application of a quantum algorithm to multiloop Feynman integrals in the Loop-Tree Duality (LTD) framework is applied to a representative four-loop topology. Bootstrapping causality in the LTD formalism, is a suitable…

Quantum Physics · Physics 2022-11-29 Andrés E. Rentería-Olivo

The computation of multi-loop multi-leg scattering amplitudes plays a key role to improve the precision of theoretical predictions for particle physics at high-energy colliders. In this work, we focus on the mathematical properties of the…

The integrand-level methods for the reduction of scattering amplitudes are well-established techniques, which have already proven their effectiveness in several applications at one-loop. In addition to the automation and refinement of tools…

High Energy Physics - Phenomenology · Physics 2012-10-05 P. Mastrolia , E. Mirabella , G. Ossola , T. Peraro , H. van Deurzen

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 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

One loop corrections to the helicity amplitudes of all 2 -> 2 subprocesses are calculated in QCD and in N=1 supersymmetric Yang-Mills theory using two versions of dimensional regularization: the `t~Hooft-Veltman scheme and dimensional…

High Energy Physics - Phenomenology · Physics 2009-10-22 Zoltan Kunszt , Adrian Signer , Zoltán Trócsányi

We present the first comprehensive analysis of the unitarity thresholds and anomalous thresholds of scattering amplitudes at two loops and beyond based on the loop-tree duality, and show how non-causal unphysical thresholds are locally…

This is part of a series of papers describing the new curve integral formalism for scattering amplitudes of the colored scalar tr$\phi^3$ theory. We show that the curve integral manifests a very surprising fact about these amplitudes: the…

High Energy Physics - Theory · Physics 2024-10-01 Nima Arkani-Hamed , Hadleigh Frost , Giulio Salvatori , Pierre-Guy Plamondon , Hugh Thomas

The unitarity method for calculating one-loop amplitudes provides algorithms of polynomial complexity. This is primarily beneficial for the computation of multi-leg one loop amplitudes and it is therefore of great interest to develop a…

High Energy Physics - Phenomenology · Physics 2009-04-14 R. Keith Ellis , Walter T. Giele , Zoltan Kunszt

We initiate a study of non-supersymmetric Born-Infeld electrodynamics in 4d at the quantum level. Explicit all-multiplicity expressions are calculated for the purely rational one-loop amplitudes in the self-dual ($++\ldots+$) and…

High Energy Physics - Theory · Physics 2020-03-18 Henriette Elvang , Marios Hadjiantonis , Callum R. T. Jones , Shruti Paranjape

Effective field theories are useful tools to search for physics beyond the Standard Model (SM). However, effective theories can lead to non-unitary behavior with fastly growing amplitudes. This unphysical behavior may lead to large…

High Energy Physics - Phenomenology · Physics 2022-01-19 Iñigo Asiáin , Domènec Espriu , Federico Mescia

We develop a spinor helicity formalism for five-dimensional scattering amplitudes of any mass and spin configuration. While five-dimensional spinor helicity variables have been previously studied in the context of N=2,4 supersymmetric…

High Energy Physics - Theory · Physics 2024-05-16 Andrzej Pokraka , Smita Rajan , Lecheng Ren , Anastasia Volovich , W. Wayne Zhao

We identify a large class of one-loop amplitudes for massless particles that can be constructed via unitarity from tree amplitudes, without any ambiguities. One-loop amplitudes for massless supersymmetric gauge theories fall into this…

High Energy Physics - Phenomenology · Physics 2010-11-15 Z. Bern , L. Dixon , D. C. Dunbar , D. A. Kosower

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

This thesis is concerned with the study of scattering amplitudes in four-dimensional conformal field theories, more particularly the N=4 super-Yang-Mills theory. We study this theory first at tree level by using twistor space techniques and…

High Energy Physics - Theory · Physics 2008-10-09 C. Vergu

The simplification and reorganization of complex expressions lies at the core of scientific progress, particularly in theoretical high-energy physics. This work explores the application of machine learning to a particular facet of this…

High Energy Physics - Theory · Physics 2025-02-05 Clifford Cheung , Aurélien Dersy , Matthew D. Schwartz

As continuation of our previous paper we further develop our new method for calculating helicity amplitudes of jet-like QED processes described by tree diagrams, applying it to lepton pair production. This method consists in replacing…

High Energy Physics - Phenomenology · Physics 2011-09-13 C. Carimalo , A. Schiller , V. G. Serbo