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Related papers: Generalised Unitarity At One-Loop With Massive Fer…

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We show how generalised unitarity cuts in D = 4 - 2 epsilon dimensions can be used to calculate efficiently complete one-loop scattering amplitudes in non-supersymmetric Yang-Mills theory. This approach naturally generates the rational…

High Energy Physics - Theory · Physics 2009-11-11 Andreas Brandhuber , Simon McNamara , Bill Spence , Gabriele Travaglini

The possibility of treating colour in one-loop amplitude calculations alike the other quantum numbers is briefly discussed for semi-numerical algorithms based on generalized unitarity and parametric integration techniques. Numerical results…

High Energy Physics - Phenomenology · Physics 2015-03-17 Jan Winter

We present a new approach to Reggeization of gauge amplitudes based on the universal properties of their infrared singularities. Using the "dipole formula", a compact ansatz for all infrared singularities of massless amplitudes, we study…

High Energy Physics - Phenomenology · Physics 2013-05-30 Vittorio Del Duca , Claude Duhr , Einan Gardi , Lorenzo Magnea , Chris D. White

In this paper, we present an improvement of a method for computing scattering amplitudes that include external (polarized) fermions with the following features: the formulas are quite general and work for different kinematic configurations…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. Chopin

We extend the known Universal One-Loop Effective Action (UOLEA) by all operators which involve scalars and fermions, not including contributions arising from open covariant derivatives. Our generic analytic expressions for the one-loop…

High Energy Physics - Phenomenology · Physics 2020-01-29 Michael Krämer , Benjamin Summ , Alexander Voigt

We show how the holomorphic anomaly found in hep-th/0409245 can be used to efficiently compute certain classes of unitarity cuts of one-loop N=4 amplitudes of gluons. These classes include all cuts of n-gluon one-loop MHV amplitudes and of…

High Energy Physics - Theory · Physics 2007-05-23 Freddy Cachazo

We investigate the inhomogeneous unitary Fermi gas and use the long-wavelength properties to predict the energies of small clusters of unitary fermions trapped in harmonic potentials. The large pairing gap and scale invariance place severe…

Quantum Gases · Physics 2015-06-22 J. Carlson , S. Gandolfi

We study the renormalization group of generic effective field theories that include gravity. We follow the on-shell amplitude approach, which provides a simple and efficient method to extract anomalous dimensions avoiding complications from…

High Energy Physics - Theory · Physics 2022-04-13 Pietro Baratella , Dominik Haslehner , Maximilian Ruhdorfer , Javi Serra , Andreas Weiler

We present general one-loop contributions to the decay processes $H\rightarrow f\bar{f}\gamma$ including all possible the exchange of the additional heavy vector gauge bosons, heavy fermions, and charged (also neutral) scalar particles in…

High Energy Physics - Phenomenology · Physics 2022-04-20 Vo Van On , Dzung Tri Tran , Chi Linh Nguyen , Khiem Hong Phan

We present analytic expressions for the one-loop QCD helicity amplitudes contributing to top-quark pair production in association with a photon or a jet at the Large Hadron Collider (LHC), evaluated through $\mathcal{O}(\epsilon^2)$ in the…

High Energy Physics - Phenomenology · Physics 2026-05-15 Souvik Bera , Colomba Brancaccio , Dhimiter Canko , Heribertus Bayu Hartanto

I describe a method for determining the coefficients of scalar integrals for one-loop amplitudes in quantum field theory. The method is based upon generalized unitarity and the behavior of amplitudes when the free parameters of the cut…

High Energy Physics - Phenomenology · Physics 2008-05-12 William B. Kilgore

We present a Mathematica package that takes any reductive gauge algebra and fully-reducible fermion representation, and outputs all semisimple gauge extensions under the condition that they have no additional fermions, and are free of local…

High Energy Physics - Phenomenology · Physics 2023-06-30 Andrew Gomes , Maximillian Ruhdorfer , Joseph Tooby-Smith

In this work we propose to use leading singularities to obtain the classical pieces of amplitudes of two massive particles whose only interaction is gravitational. Leading singularities are generalizations of unitarity cuts. At one-loop we…

High Energy Physics - Theory · Physics 2017-05-30 Freddy Cachazo , Alfredo Guevara

We present a calculation of the rational terms in two-loop all-plus gluon amplitudes using $D$-dimensional unitarity. We use a conjecture of separability of the two loops, and then a simple generalization of one-loop $D$-dimensional…

High Energy Physics - Phenomenology · Physics 2022-06-30 David A. Kosower , Sebastian Pögel

We review the recently developed bootstrap method for the computation of high-multiplicity QCD amplitudes at one loop. We illustrate the general algorithm step by step with a six-point example. The method combines (generalized) unitarity…

High Energy Physics - Phenomenology · Physics 2008-11-26 Carola F. Berger

Generalized unitarity cut of a Feynman diagram generates an algebraic system of polynomial equations. At high-loop levels, these equations may define a complex curve or a (hyper-)surface with complicated topology. We study the curve cases,…

High Energy Physics - Phenomenology · Physics 2015-06-12 Rijun Huang , Yang Zhang

Light cone perturbation theory has become an essential tool to calculate cross sections for various small-$x$ dilute-dense processes such as deep inelastic scattering and forward proton-proton and proton-nucleus collisions. Here we set out…

High Energy Physics - Phenomenology · Physics 2017-04-05 Tuomas Lappi , Risto Paatelainen

We describe techniques that simplify the calculation of one-loop QCD amplitudes with many external legs, which are needed for next-to-leading-order (NLO) corrections to multi-jet processes. The constraints imposed by perturbative unitarity,…

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

We present a formalism for the calculation of multi-particle one-loop amplitudes, valid for an arbitrary number N of external legs, and for massive as well as massless particles. A new method for the tensor reduction is suggested which…

High Energy Physics - Phenomenology · Physics 2013-12-16 T. Binoth , J. Ph. Guillet , G. Heinrich , E. Pilon , C. Schubert

We present a generalized unitarity method for theories of point-particle worldlines coupled to gravity, analogous to that of scattering amplitudes in quantum field theory. This method allows the computation of perturbative observables from…

High Energy Physics - Theory · Physics 2026-02-25 Vincent F. He , Julio Parra-Martinez