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A way to efficiently compute helicity amplitudes for arbitrary tree-level scattering processes in QCD is presented. The scattering amplitude is evaluated recursively through a set of Dyson-Schwinger equations. The computational cost of this…

High Energy Physics - Phenomenology · Physics 2009-11-11 Costas G. Papadopoulos , Malgorzata Worek

The rational parts of 6-gluon one-loop amplitudes with scalars circulating in the loop are computed by using the newly developed method for computing the rational parts directly from Feynman integrals. We present the analytic results for…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zhi-Guang Xiao , Gang Yang , Chuan-Jie Zhu

We present an alternative approach for calculating helicity amplitudes for processes involving both massless and massive fermions. With this method one can easily obtain covariant expressions for the helicity amplitudes. The final…

High Energy Physics - Phenomenology · Physics 2014-11-17 R. Vega , J. Wudka

This article deals with a generalization of the superadiabatic projectors method. In a general framework, the well-known superadiabatic projectors are constructed and accurately described in the case of rank one, when a remarkable…

Spectral Theory · Mathematics 2025-01-27 Lino Benedetto , Clotilde Fermanian Kammerer , Nicolas Raymond , Éric Vacelet

We sketch a staged plan for a series of muon-based facilities that can do compelling physics at each stage. Such a plan is unique in its ability to span both the Intensity and Energy Frontiers as defined by the P5 sub-panel of the US High…

Accelerator Physics · Physics 2019-08-13 Daniel M. Kaplan

We present an expression for the QCD amplitude for a general hard scattering process with any number of soft gluon emissions, to one-loop accuracy. The amplitude is written in two different but equivalent ways: as a product of operators…

High Energy Physics - Phenomenology · Physics 2016-06-01 René Ángeles-Martínez , Jeffrey R. Forshaw , Michael H. Seymour

Following the construction of the projection operators on $T^2$ presented by Gopakumar, Headrick and Spradlin, we construct a set of projection operators on the integral noncommutative orbifold $T^2/G (G=Z_N, N=2, 3, 4, 6)$ which correspond…

High Energy Physics - Theory · Physics 2009-06-11 Hou Bo-yu , Shi Kangjie , Yang Zhan-ying

The spectrum of $L^2$ on a pseudo-unitary group $U(p,q)$ (we assume $p\ge q$ naturally splits into $q+1$ types. We write explicitly orthogonal projectors in $L^2$ to subspaces with uniform spectra (this is an old question formulated by…

Representation Theory · Mathematics 2018-12-14 Yury A. Neretin

We present an explicit expression for a particular $n$-gluon two loop scattering partial amplitude. Specifically we present an analytic form for the single trace $N_c$ independent colour partial amplitude for the case where all external…

High Energy Physics - Phenomenology · Physics 2020-04-08 David C. Dunbar , Warren B. Perkins , Joseph M. W. Strong

Using the helicity formalism, we compute the corrections to the tree-level multigluon amplitudes in the high-energy limit, induced by the corrections to the multi-Regge kinematics, and we show that they coincide with the corresponding…

High Energy Physics - Phenomenology · Physics 2016-08-24 Vittorio Del Duca

In this paper, we prove strict Frechet differentiability of the metric projection operator onto closed balls in Hilbert spaces, and we find exact expressions for Frechet derivatives. Since Frechet differentiability implies Gateaux…

Functional Analysis · Mathematics 2024-01-11 Jinlu Li

The spinor-helicity formalism is an essential technique of the amplitudes community. We draw on this method to construct a scheme for classifying higher-dimensional spacetimes in the style of the four-dimensional Petrov classification and…

General Relativity and Quantum Cosmology · Physics 2019-04-02 Ricardo Monteiro , Isobel Nicholson , Donal O'Connell

In this article, the importance is demonstrated of a proper choice of reference particles for decay angle definitions, when constructing partial-wave amplitude of multi-body decays using helicity formalism. This issue is often ignored in…

High Energy Physics - Experiment · Physics 2021-07-07 Mengzhen Wang , Yi Jiang , Yinrui Liu , Wenbin Qian , Xiaorui Lyu , Liming Zhang

In this paper, we present a mathematical model for the angular projection of a rectangular arrangement of points in a grid. This simple, yet interesting problem, has both a scholarly value and applications for data extraction techniques to…

General Physics · Physics 2015-02-05 Ashmeet Singh

An integral equation-based numerical method for scattering from multi-dielectric cylinders is presented. Electromagnetic fields are represented via layer potentials in terms of surface densities with physical interpretations. The existence…

Computational Physics · Physics 2019-05-01 Johan Helsing , Anders Karlsson

We develop a formalism to compute non-perturbative 5-point scattering amplitudes and apply it to gravitational waveforms in the two-body problem for arbitrary trajectories. Drawing inspiration from Feshbach's projector formalism in nuclear…

High Energy Physics - Theory · Physics 2026-04-21 Katsuki Aoki , Andrea Cristofoli

We study the partial-wave expansion of residues of five-point tree-amplitude involving identical scalar particles in the external legs. We check the construction using massive spinor-helicity building blocks and by matching to the…

High Energy Physics - Theory · Physics 2026-01-22 Arnab Priya Saha , Aninda Sinha

We study the helicity amplitudes describing the quasielastic production of vector mesons in deep inelastic scattering within the context of the model which we previously introduced to describe the ratio of longitudinal to transverse cross…

High Energy Physics - Phenomenology · Physics 2014-11-17 I. Royen

We derive a set of criteria to decide whether a given projection measurement can be, in principle, exactly implemented solely by means of linear optics. The derivation can be adapted to various detection methods, including photon counting…

Quantum Physics · Physics 2016-08-16 Peter van Loock , Norbert Lütkenhaus

Spectral projectors of second order differential operators play an important role in quantum physics and other scientific and engineering applications. In order to resolve local features and to obtain converged results, typically the number…

Numerical Analysis · Mathematics 2019-01-30 Yingzhou Li , Lin Lin