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We analyse the singular behaviour of one-loop integrals and scattering amplitudes in the framework of the loop--tree duality approach. We show that there is a partial cancellation of singularities at the loop integrand level among the…

High Energy Physics - Phenomenology · Physics 2015-06-19 Sebastian Buchta , Grigorios Chachamis , Petros Draggiotis , Ioannis Malamos , German Rodrigo

In this review, we discuss recent developments concerning efficient calculations of multi-loop multi-leg scattering amplitudes. Inspired by the remarkable properties of the Loop-Tree Duality (LTD), we explain how to reconstruct an integrand…

High Energy Physics - Phenomenology · Physics 2021-09-30 German F. R. Sborlini

We extend useful properties of the $H\to\gamma\gamma$ unintegrated dual amplitudes from one- to two-loop level, using the Loop-Tree Duality formalism. In particular, we show that the universality of the functional form -- regardless of the…

High Energy Physics - Phenomenology · Physics 2019-03-27 Felix Driencourt-Mangin , German Rodrigo , German F. R. Sborlini , William J. Torres Bobadilla

Characterizing multiloop topologies is an important step towards developing novel methods at high perturbative orders in quantum field theory. In this article, we exploit the Loop-Tree Duality (LTD) formalism to analyse multiloop topologies…

High Energy Physics - Phenomenology · Physics 2022-11-08 Selomit Ramírez-Uribe , Roger J. Hernández-Pinto , Germán Rodrigo , German F. R. Sborlini

We extend the four-dimensional unsubtraction method, which is based on the loop-tree duality (LTD), to deal with processes involving heavy particles. The method allows to perform the summation over degenerate IR configurations directly at…

High Energy Physics - Phenomenology · Physics 2016-11-23 German F. R. Sborlini , Felix Driencourt-Mangin , German Rodrigo

In the context of high-energy particle physics, a reliable theory-experiment confrontation requires precise theoretical predictions. This translates into accessing higher-perturbative orders, and when we pursue this objective, we inevitably…

High Energy Physics - Phenomenology · Physics 2024-09-12 German Sborlini

We describe a new method to perform NLO calculations, combining real and virtual amplitudes at the integrand level, with a fully local compensation between them in the IR, and between the virtual integrand and properly defined counter-terms…

High Energy Physics - Phenomenology · Physics 2016-08-08 German Rodrigo , Felix Driencourt-Mangin , German F. R. Sborlini , Roger Jose Hernandez-Pinto

We study scalar one-loop amplitudes in massive $\phi^3$-theory within causal loop-tree duality. We derive a recurrence relation for the integrand of the amplitude. The integrand is by construction free of spurious singularities on…

High Energy Physics - Theory · Physics 2022-10-07 Sascha Kromin , Niklas Schwanemann , Stefan Weinzierl

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…

Using loop-tree duality, we relate a renormalised $n$-point $l$-loop amplitude in a quantum field theory to a phase-space integral of a regularised $l$-fold forward limit of a UV-subtracted $(n+2l)$-point tree-amplitude-like object. We show…

High Energy Physics - Phenomenology · Physics 2020-07-01 Robert Runkel , Zoltán Szőr , Juan Pablo Vesga , Stefan Weinzierl

The abundance of infrared singularities in gauge theories due to unresolved emission of massless particles (soft and collinear) represents the main difficulty in perturbative calculations. They are typically regularized in dimensional…

High Energy Physics - Phenomenology · Physics 2016-03-23 Roger J. Hernandez-Pinto , German F. R. Sborlini , German Rodrigo

Unveiling hidden symmetries within Feynman diagrams is crucial for achieving more efficient computations in high-energy physics. In this paper, we study the symmetries underlying the causal Loop-Tree Duality (LTD) representations through a…

High Energy Physics - Theory · Physics 2025-05-12 Irene Lopez Imaz , German Sborlini

In this talk, we review the basis of the loop-tree duality theorem, which allows to rewrite loop scattering amplitudes in terms of tree-level like objects. Since the loop measure is converted into a phase-space one, both virtual and real…

High Energy Physics - Phenomenology · Physics 2016-11-16 German F. R. Sborlini , Felix Driencourt-Mangin , Roger Hernandez-Pinto , German Rodrigo

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

Though the one-loop amplitudes of the Higgs boson to massless gauge bosons are finite because there is no direct interaction at tree-level in the Standard Model, a well-defined regularization scheme is still required for their correct…

High Energy Physics - Phenomenology · Physics 2018-03-22 Felix Driencourt-Mangin , German Rodrigo , German F. R. Sborlini

We describe the calculation of the one-loop corrections to $H \to \gamma \gamma$ and $g g \to H$ within the four-dimensional unsubtraction/loop-tree duality (FDU/LTD) approach. The fact that these corrections are both IR and UV finite is…

High Energy Physics - Phenomenology · Physics 2017-09-29 German F. R. Sborlini , Felix Driencourt-Mangin , German Rodrigo

We present an overview of the analysis of the multiloop topologies that appear for the first time at four loops and the assembly of them in a general expression, the N$^4$MLT universal topology. Based on the fact that the Loop-Tree Duality…

A general outlook is presented on the study of multiloop topologies appearing for the first time at four loops. A unified description and representation of this family is provided, the so-called N$^4$MLT universal topology. Based on the…

High Energy Physics - Theory · Physics 2021-12-13 Selomit Ramírez-Uribe

First results towards a general method for asymptotic expansions of Feynman amplitudes in the loop-tree duality (LTD) formalism are presented. The asymptotic expansion takes place at integrand-level in the Euclidean space of the loop…

High Energy Physics - Phenomenology · Physics 2021-05-05 Judith Plenter , Germán Rodrigo

Loop-tree duality allows to express virtual contributions in terms of phase-space integrals, thus leading to a direct comparison with real radiation terms. In this talk, we review the basis of the method and describe its application to…

High Energy Physics - Phenomenology · Physics 2016-01-21 German F. R. Sborlini