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Related papers: Four-loop scattering amplitudes through the loop-t…

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Loop Tree Duality (LTD) offers a promising avenue to numerically integrate multi-loop integrals directly in momentum space. It is well-established at one loop, but there have been only sparse numerical results at two loops. We provide a…

High Energy Physics - Phenomenology · Physics 2019-10-16 Zeno Capatti , Valentin Hirschi , Dario Kermanschah , Ben Ruijl

We develop a manifestly supersymmetric version of the generalized unitarity cut method for calculating scattering amplitudes in N=4 SYM theory. We illustrate the power of this method by computing the one-loop n-point NMHV super-amplitudes.…

High Energy Physics - Theory · Physics 2015-05-13 J. M. Drummond , J. Henn , G. P. Korchemsky , E. Sokatchev

We derive a duality relation between one-loop integrals and phase-space integrals emerging from them through single cuts. The duality relation is realized by a modification of the customary +i0 prescription of the Feynman propagators. The…

High Energy Physics - Phenomenology · Physics 2009-09-17 Stefano Catani , Tanju Gleisberg , Frank Krauss , German Rodrigo , Jan-Christopher Winter

We present a new formulation of the loop-tree duality theorem for higher loop diagrams valid both for massless and massive cases. $l$-loop integrals are expressed as weighted sum of trees obtained from cutting $l$ internal propagators of…

High Energy Physics - Phenomenology · Physics 2019-11-22 Robert Runkel , Zoltán Szőr , Juan Pablo Vesga , Stefan Weinzierl

We present a new algorithm to construct a purely four dimensional representation of higher-order perturbative corrections to physical cross-sections at next-to-leading order (NLO). The algorithm is based on the loop-tree duality (LTD), and…

High Energy Physics - Phenomenology · Physics 2016-09-12 German F. R. Sborlini , Felix Driencourt-Mangin , Roger Hernandez-Pinto , German Rodrigo

We review the recent progress on the numerical implementation of the Loop-Tree Duality Method (LTDM) for the calculation of scattering amplitudes. A central point is the analysis of the singularities of the integrand. In the framework of…

High Energy Physics - Phenomenology · Physics 2015-09-25 Sebastian Buchta , Grigorios Chachamis , Petros Draggiotis , Ioannis Malamos , German Rodrigo

We present the first proof-of-concept application to decay processes at higher perturbative orders of LTD causal unitary, a novel methodology that exploits the causal properties of vacuum amplitudes in the loop-tree duality (LTD) and is…

We propose multiloop vacuum amplitudes as the optimal building blocks for efficiently assembling theoretical predictions at high-energy colliders. This hypothesis is strongly supported by the manifestly causal properties of the loop-tree…

High Energy Physics - Phenomenology · Physics 2024-12-06 Selomit Ramírez-Uribe , Prasanna K. Dhani , German F. R. Sborlini , Germán Rodrigo

One of the most severe bottlenecks to reach high-precision predictions in QFT is the calculation of multiloop multileg Feynman integrals. Several new strategies have been proposed in the last years, allowing impressive results with deep…

High Energy Physics - Theory · Physics 2023-09-27 German F. R. Sborlini

We describe a systematic approach for the evaluation of Witten diagrams for multi-loop scattering amplitudes of a conformally coupled scalar $\phi^4$-theory in Euclidean AdS$_4$, by recasting the Witten diagrams as flat space Feynman…

High Energy Physics - Theory · Physics 2022-08-24 Till Heckelbacher , Ivo Sachs , Evgeny Skvortsov , Pierre Vanhove

This is the first in a series of papers presenting a new understanding of scattering amplitudes based on fundamentally combinatorial ideas in the kinematic space of the scattering data. We study the simplest theory of colored scalar…

High Energy Physics - Theory · Physics 2024-10-01 N. Arkani-Hamed , H. Frost , G. Salvatori , P-G. Plamondon , H. Thomas

It was recently proposed that the leading singularities of the S-Matrix of N = 4 super Yang-Mills theory arise as the residues of a contour integral over a Grassmannian manifold, with space-time locality encoded through residue theorems…

High Energy Physics - Theory · Physics 2015-05-14 Jared Kaplan

This thesis is focused on the development of new mathematical methods for computing multi-loop scattering amplitudes in gauge theories. In this work we combine, for the first time, the unitarity-based construction for integrands, and the…

High Energy Physics - Phenomenology · Physics 2014-10-21 Ulrich Schubert

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

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

We introduce a novel construction of a contour deformation within the framework of Loop-Tree Duality for the numerical computation of loop integrals featuring threshold singularities in momentum space. The functional form of our contour…

High Energy Physics - Phenomenology · Physics 2020-11-24 Zeno Capatti , Valentin Hirschi , Dario Kermanschah , Andrea Pelloni , Ben Ruijl

The duality relation between one-loop integrals and phase-space integrals, developed in a previous work, is extended to higher-order loops. The duality relation is realized by a modification of the customary +i0 prescription of the Feynman…

High Energy Physics - Phenomenology · Physics 2011-03-17 Isabella Bierenbaum , Stefano Catani , Petros Draggiotis , German Rodrigo

We introduce a new technique to generate scattering amplitudes at one loop. Traditional tree algorithms, which handle diagrams with fixed momenta, are promoted to generators of loop-momentum polynomials that we call open loops. Combining…

High Energy Physics - Phenomenology · Physics 2013-05-30 Fabio Cascioli , Philipp Maierhöfer , Stefano Pozzorini

A method for calculating loop amplitudes at the multiboson threshold is presented, based on Feynman-diagram techniques. We explicitly calculate the one-loop amplitudes in both $\phi^4$-symmetric and broken symmetry cases, using dimensional…

High Energy Physics - Phenomenology · Physics 2009-10-22 E. N. Argyres , Ronald H. P. Kleiss , Costas G. Papadopoulos

We relate a $l$-loop Feynman integral to a sum of phase space integrals, where the integrands are determined by the spanning trees of the original $l$-loop graph. Causality requires that the propagators of the trees have a modified…

High Energy Physics - Phenomenology · Physics 2019-08-07 Robert Runkel , Zoltán Szőr , Juan Pablo Vesga , Stefan Weinzierl