English
Related papers

Related papers: Loop Integrands for Scattering Amplitudes from the…

200 papers

We present the building blocks that can be combined to produce tree-level S-matrix elements of a variety of theories with various spins mixed in arbitrary dimensions. The new formulas for the scattering of $n$ massless particles are given…

High Energy Physics - Theory · Physics 2015-06-23 Freddy Cachazo , Song He , Ellis Ye Yuan

The maximally supersymmetric Yang-Mills theory in four-dimensional Minkowski space is an exceptional model of mathematical physics. Even more so in the planar limit, where the theory is believed to be integrable. In particular, the…

High Energy Physics - Theory · Physics 2018-11-16 Nils Kanning

We present a novel type of differential equations for on-shell loop integrals. The equations are second-order and importantly, they reduce the loop level by one, so that they can be solved iteratively in the loop order. We present several…

High Energy Physics - Theory · Physics 2011-04-22 James M. Drummond , Johannes M. Henn , Jaroslav Trnka

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

We present all-multiplicity formulae, derived from first principles in the MHV sector and motivated by twistor string theory for general helicities, for the tree-level S-matrix of gluon scattering on self-dual radiative backgrounds. These…

High Energy Physics - Theory · Physics 2023-05-11 Tim Adamo , Lionel Mason , Atul Sharma

Supergravity theories with non-minimal K\"ahler potentials are characterized by a non-trivial field space manifold with corresponding non-trivial kinetic terms. The scattering amplitudes in these theories can be calculated at fixed…

High Energy Physics - Theory · Physics 2023-02-14 Emilian Dudas , Tony Gherghetta , Keith A. Olive , Sarunas Verner

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 investigate in the context of the scattering equations, how one-loop linear propagator integrands in gauge theories can be linked to integrands with quadratic propagators using a double forward limit. We illustrate our procedure through…

High Energy Physics - Theory · Physics 2020-09-09 Johannes Agerskov , N. E. J. Bjerrum-Bohr , Humberto Gomez , Cristhiam Lopez-Arcos

We present a method to compute the integrands of one-loop Einstein-Yang-Mills amplitudes for any number of external gauge and gravity multiplets. Our construction relies on the double-copy structure of Einstein-Yang-Mills as…

High Energy Physics - Theory · Physics 2023-03-01 Franziska Porkert , Oliver Schlotterer

In this letter, we generalize the recursion methods based on cut equations arXiv:2412.21027, originally developed for scalar theories, to gluons in pure Yang-Mills theory. In gauge theories, planar loop integrands are subtle to defined and…

High Energy Physics - Theory · Physics 2025-03-21 Qu Cao , Fan Zhu

We propose a procedure to determine the moduli-space integrands of loop-level superstring amplitudes for massless external states in terms of the field theory limit. We focus on the type II superstring. The procedure is to: (i) take a…

High Energy Physics - Theory · Physics 2021-11-19 Yvonne Geyer , Ricardo Monteiro , Ricardo Stark-Muchão

We demonstrate that loop integrands of (super-)gravity scattering amplitudes possess surprising properties in the ultraviolet (UV) region. In particular, we study the scaling of multi-particle unitarity cuts for asymptotically large momenta…

High Energy Physics - Theory · Physics 2021-02-16 Alex Edison , Enrico Herrmann , Julio Parra-Martinez , Jaroslav Trnka

We translate between different formulations of Yangian invariants relevant for the computation of tree-level scattering amplitudes in N=4 super-Yang--Mills theory. While the R-operator formulation allows to relate scattering amplitudes to…

High Energy Physics - Theory · Physics 2014-08-27 Johannes Broedel , Marius de Leeuw , Matteo Rosso

We calculate one-loop scattering amplitudes in N=4 super Yang-Mills theory away from the origin of the moduli space and demonstrate that the results are extremely simple, in much the same way as in the conformally invariant theory.…

High Energy Physics - Theory · Physics 2015-02-23 Robert M. Schabinger

In this letter, we extend the tree-level Kawai--Lewellen--Tye (KLT) and Bern--Carrasco--Johansson (BCJ) amplitude relations to loop integrands of gauge theory and gravity. By rearranging the propagators of gauge and gravity loop integrands,…

High Energy Physics - Theory · Physics 2017-06-15 Song He , Oliver Schlotterer

Britto, Cachazo and Feng have recently derived a recursion relation for tree-level scattering amplitudes in Yang-Mills. This relation has a bilinear structure inherited from factorisation on multi-particle poles of the scattering amplitudes…

High Energy Physics - Theory · Physics 2008-11-26 James Bedford , Andreas Brandhuber , Bill Spence , Gabriele Travaglini

We formulate new integration rules for one-loop scattering equations analogous to those at tree-level, and test them in a number of non-trivial cases for amplitudes in scalar $\phi^3$-theory. This formalism greatly facilitates the…

High Energy Physics - Theory · Physics 2016-01-20 Christian Baadsgaard , N. E. J. Bjerrum-Bohr , Jacob L. Bourjaily , Poul H. Damgaard , Bo Feng

We attempt to systematically derive tree-level scattering amplitudes in four-dimensional, planar, maximally supersymmetric Yang-Mills theory from integrability. We first review the connections between integrable spin chains, Yangian…

High Energy Physics - Theory · Physics 2019-04-15 Nils Kanning , Matthias Staudacher

Scattering amplitudes in superconformal field theories do not enjoy this symmetry, because the definition of asymptotic states involve a notion of infinity. Concentrating on planar $\mathcal{N}=4$ Yang-Mills, we consider a generalization of…

High Energy Physics - Theory · Physics 2015-05-28 Simon Caron-Huot

We derive a recursion relation for loop-level scattering amplitudes of Lagrangian field theories that generalises the tree-level Berends-Giele recursion relation in Yang-Mills theory. The origin of this recursion relation is the homological…

High Energy Physics - Theory · Physics 2020-07-07 Branislav Jurco , Tommaso Macrelli , Christian Saemann , Martin Wolf