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Related papers: Maximal Unitarity at Two Loops

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We give an explicit formula for all tree amplitudes in N=4 SYM, derived by solving the recently presented supersymmetric tree-level recursion relations. The result is given in a compact, manifestly supersymmetric form and we show how to…

High Energy Physics - Theory · Physics 2009-04-17 J. M. Drummond , J. M. Henn

In this note we derive an explicit modular invariant formula for the two loop 4-point amplitude in superstring theory in terms of a multiple integral (7 complex integration variables) over the complex plane which is shown to be convergent.…

High Energy Physics - Theory · Physics 2009-10-31 Roberto Iengo , Chuan-Jie Zhu

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 a numerical implementation of generalized unitarity. We will show that we are able to obtain the box coefficients of any 1 loop gluonic amplitude, for an arbitrary helicity configuration and for any number of external particles.

High Energy Physics - Phenomenology · Physics 2008-01-15 Petros Draggiotis

We compute the four-point amplitude with external adjoint particles in $\mathcal{N}=2$ SCQCD at two loops using $\mathcal{N}=1$ superspace Feynman diagrams, extending the results of arXiv:1406.7283. We consider the diagrammatic difference…

High Energy Physics - Theory · Physics 2015-06-15 Marta Leoni , Andrea Mauri , Alberto Santambrogio

In the Type II superstring the 4-point function for massless NS-NS bosons at one-loop is well known [1][14]. The overall constant factor in this amplitude is very important because it needs to satisfy the unitarity and S-duality conditions…

High Energy Physics - Theory · Physics 2010-02-04 Humberto Gomez

Among the unitarity cuts of massless 4-loop propagators two classes have remained unknown until recently: 2-loop 3-particle cuts, and 1-loop 4-particle cuts. In this article we shall discuss the calculation that completes the master…

High Energy Physics - Phenomenology · Physics 2019-12-16 Vitaly Magerya , Andrey Pikelner

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…

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

We use supersymmetric generalised unitarity to calculate supercoefficients of box functions in the expansion of scattering amplitudes in N=8 supergravity at one loop. Recent advances have presented tree-level amplitudes in N=8 supergravity…

High Energy Physics - Theory · Physics 2009-09-28 Panagiotis Katsaroumpas , Bill Spence , Gabriele Travaglini

To find boundary contributions is a rather difficult problem when applying the BCFW recursion relation. In this paper, we propose an approach to bypass this problem by calculating general tree amplitudes that contain no polynomial using…

High Energy Physics - Theory · Physics 2015-06-23 Kang Zhou , Chenkai Qiao

Four-particle tree-level scattering amplitudes in string theory are magically consistent with unitarity, reflected in the non-trivial fact that beneath the critical dimension, the residues of the amplitudes on massive poles can be expanded…

High Energy Physics - Theory · Physics 2022-03-14 Nima Arkani-Hamed , Lorenz Eberhardt , Yu-tin Huang , Sebastian Mizera

We find that unitarity cuts and the duality between color and kinematics are sufficient constraints to bootstrap $D$-dimensional QCD scattering amplitudes starting from three-particle tree-level. Specifically, we calculate tree level…

High Energy Physics - Theory · Physics 2024-09-25 John Joseph M. Carrasco , Aslan Seifi

We derive non-linear recursion equations for the leading infrared logarithms in massless non-renormalizable effective field theories. The derivation is based solely on the requirements of the unitarity, analyticity and crossing symmetry of…

High Energy Physics - Phenomenology · Physics 2014-11-20 J. Koschinski , M. V. Polyakov , A. A. Vladimirov

We consider a procedure for directly constructing general tree-level four-particle scattering amplitudes of massive spinning particles that are consistent with the usual requirements of Lorentz invariance, unitarity, crossing symmetry, and…

High Energy Physics - Theory · Physics 2018-08-10 James Bonifacio , Kurt Hinterbichler

In this paper we extend the study initiated in arXiv:2302.04709v2 [hep-th] to the computation of one-loop elastic amplitudes. We consider 1+1 dimensional massive bosonic Lagrangians with polynomial-like potentials and absence of inelastic…

High Energy Physics - Theory · Physics 2024-03-08 Matheus Fabri , Davide Polvara

We use unitarity techniques to compute the two-loop non-planar corrections to the Sudakov form factor and the four-point amplitude in ABJM theory. We start by reconstructing non-planar integrals from two-particle cuts in three dimensions.…

High Energy Physics - Theory · Physics 2014-07-09 Lorenzo Bianchi , Marco S. Bianchi

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

The existence of a finite basis of algebraically independent one-loop integrals has underpinned important developments in the computation of one-loop amplitudes in field theories and gauge theories in particular. We give an explicit…

High Energy Physics - Theory · Physics 2011-10-19 Janusz Gluza , Krzysztof Kajda , David A. Kosower

We present the two-loop amplitudes for a self-dual Higgs boson with up to four positive helicity gluons in the heavy top-quark limit. Because the tree amplitudes in the all-plus sector vanish, we can construct simple representations of the…

High Energy Physics - Phenomenology · Physics 2026-05-15 Simon Badger , Christian Biello , Colomba Brancaccio , Federico Ripani