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Related papers: A Fully Numerical Approach to One-Loop Amplitudes

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Asymptotic behavior of the scattering amplitude for two scalar particles by scalar, vector and tensor exchanges at high energy and fixed momentum transfers is reconsidered in quantum field theory. In the framework of the quasi-potential…

High Energy Physics - Theory · Physics 2008-05-02 Nguyen Suan Han , Nguyen Nhu Xuan

We present a new method, exact in $\alpha'$, to explicitly compute string tree-level amplitudes involving one massive state and any number of massless ones. This construction relies on the so-called twisted heterotic string, which admits…

High Energy Physics - Theory · Physics 2021-08-04 Max Guillen , Henrik Johansson , Renann Lipinski Jusinskas , Oliver Schlotterer

We explore the relation between resummation and explicit multi-loop calculations for QCD hard-scattering amplitudes. We describe how the factorization properties of amplitudes lead to the exponentiation of double and single poles at each…

High Energy Physics - Phenomenology · Physics 2014-11-17 George Sterman , Maria E. Tejeda-Yeomans

Several problems in computer algebra can be efficiently solved by reducing them to calculations over finite fields. In this paper, we describe an algorithm for the reconstruction of multivariate polynomials and rational functions from their…

High Energy Physics - Phenomenology · Physics 2016-12-14 Tiziano Peraro

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

In this talk we describe the recursive Approach to One-loop QCD Matrix Elements.

High Energy Physics - Phenomenology · Physics 2009-11-11 N. E. J. Bjerrum-Bohr , David C. Dunbar , Harald Ita

We consider the Compton amplitude for the scattering of a photon and a (massless) ``electron/positron'' at one loop (i.e. genus one) in a four-dimensional fermionic heterotic string model. Starting from the bosonization of the world-sheet…

High Energy Physics - Theory · Physics 2009-10-30 A. Pasquinucci , M. Petrini

The recent proposal [1911.06318, 2010.07861] of implementing electric-magnetic duality rotation at the level of perturbative scattering amplitudes and its generalisation to gravitational context where usual gravitational mass is rotated to…

High Energy Physics - Theory · Physics 2021-03-08 Jung-Wook Kim , Myungbo Shim

We present compact analytic formulae for the one-loop amplitudes for Higgs + 4 parton scattering, $0 \to g g g g h$, $0 \to \bar{q} q gg h$ and $0\to \bar{q} q \bar{q}^\prime q^\prime h$, mediated by a loop of massive coloured quarks. We…

High Energy Physics - Phenomenology · Physics 2022-06-24 Lucy Budge , John M. Campbell , Giuseppe De Laurentis , R. Keith Ellis , Satyajit Seth

We describe progress applying the \textit{Worldline Formalism} of quantum field theory to the fermion propagator dressed by $N$-photons to study multi-linear Compton scattering processes, explaining how this approach -- whose calculational…

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

This paper investigates how tree-level amplitudes with massless quarks, gluons and/or massless scalars transforming under a single copy of the gauge group can be expressed in the context of the scattering equations as a sum over the…

High Energy Physics - Theory · Physics 2015-03-04 Stefan Weinzierl

It is well-known that perturbative calculations in field theory can lead to far simpler answers than the Feynman diagram approach might suggest. In some cases scattering amplitudes can be constructed for processes with any desired number of…

High Energy Physics - Theory · Physics 2007-10-31 James Bedford

We evaluate one-loop finite-time amplitudes for graviton scattering in Matrix theory and compare to the corresponding amplitudes in supergravity. We find agreement for arbitrary time intervals at leading order in distance, providing a…

High Energy Physics - Theory · Physics 2009-10-30 Oyvind Tafjord , Vipul Periwal

We compute two infinite series of tree-level amplitudes with a massive scalar pair and an arbitrary number of gluons. We provide results for amplitudes where all gluons have identical helicity, and amplitudes with one gluon of opposite…

High Energy Physics - Theory · Physics 2009-11-11 Darren Forde , David A. Kosower

General equations for the calculation of amplitudes are presented. As an illustration of application of proposed formulae we calculate electron-electron scattering amplitudes.

High Energy Physics - Phenomenology · Physics 2007-05-23 Alexander L. Bondarev

Asymptotic behavior of the scattering amplitude for two scalar particles by scalar, vector and tensor exchanges at high energy and fixed momentum transfers is reconsidered in quantum field theory. In the framework of the quasi-potential…

High Energy Physics - Theory · Physics 2015-06-03 Nguyen Suan Han , Le Hai Yen , Nguyen Nhu Xuan

Splitting amplitudes govern the behavior of scattering amplitudes at the momenta of external legs become collinear. In this talk we outline the calculation of two-loop splitting amplitudes via the unitarity sewing method. This method…

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

Making use of the geometric formulation of the Standard Model Effective Field Theory we calculate the one-loop tadpole diagrams to all orders in the Standard Model Effective Field Theory power counting. This work represents the first…

High Energy Physics - Phenomenology · Physics 2022-02-07 T. Corbett

An efficient numerical algorithm to evaluate one-loop amplitudes using tensor integrals is presented. In particular, it is shown by explicit calculations that for ordered QCD amplitudes with a number of external legs up to 10, its…

High Energy Physics - Phenomenology · Physics 2009-08-11 A. van Hameren