English
Related papers

Related papers: Automated one-loop calculations: a proof of concep…

200 papers

We present an analytic reconstruction of one-loop amplitudes for the process $0 \to \bar{q}qt\bar{t}H$. Our calculation is a novel use of analytic reconstruction, retaining explicit covariance in the massive spin states through the massive…

High Energy Physics - Phenomenology · Physics 2025-07-28 John M. Campbell , Giuseppe De Laurentis , R. Keith Ellis

We present the version 2.0 of the program package GoSam for the automated calculation of one-loop amplitudes. GoSam is devised to compute one-loop QCD and/or electroweak corrections to multi-particle processes within and beyond the Standard…

In order to meet the precision requirements for the LHC and future colliders, next-to-next-to-leading order corrections to a wide range of processes are essential, making general automated tools highly desirable. Extending the strategy of…

High Energy Physics - Phenomenology · Physics 2026-03-09 Fabian Lange , Max F. Zoller

We present the program package GoSam which is designed for the automated calculation of one-loop amplitudes for multi-particle processes in renormalisable quantum field theories. The amplitudes, which are generated in terms of Feynman…

The program package GoSam is presented which aims at the automated calculation of one-loop amplitudes for multi-particle processes. The amplitudes are generated in terms of Feynman diagrams and can be reduced using either D-dimensional…

High Energy Physics - Phenomenology · Physics 2015-06-03 G. Cullen , N. Greiner , G. Heinrich , G. Luisoni , P. Mastrolia , G. Ossola , T. Reiter , F. Tramontano

Two program packages are presented for evaluating one-loop amplitudes. They can work either in dimensional regularization or in constrained differential renormalization. The latter method is found at the one-loop level to be equivalent to…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. Hahn , M. Perez-Victoria

We report our experiences with the generalized integration-by-parts algorithm [hep-ph/9609429] in the context of calculations of a realistic one-loop subset of diagrams.

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Yu. Bardin , L. V. Kalinovskaya , F. V. Tkachov

We present a new method for computing complete one-loop amplitudes, including their rational parts, in non-supersymmetric gauge theory. This method merges the unitarity method with on-shell recursion relations. It systematizes a…

High Energy Physics - Phenomenology · Physics 2010-11-15 Zvi Bern , Lance J. Dixon , David A. Kosower

A number theoretic algorithm is given for writing gauge theory amplitudes in a compact manner. It is possible to write down all details of the complete $L$ loop amplitude with two integers, or a complex integer. However, a more symmetric…

General Physics · Physics 2007-05-23 Gordon Chalmers

We calculate all planar contributions to the two-loop massless helicity amplitudes for the process $q\bar q\to \gamma\gamma\gamma$. The results are presented in fully analytic form in terms of the functional basis proposed recently by…

High Energy Physics - Phenomenology · Physics 2021-08-25 Herschel A. Chawdhry , Michal Czakon , Alexander Mitov , Rene Poncelet

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

We present the two-loop helicity amplitudes contributing to the next-to-next-to-leading order QCD predictions for W-boson production in association with two photons at the Large Hadron Collider. We derived compact analytic expressions for…

High Energy Physics - Phenomenology · Physics 2024-09-27 Simon Badger , Heribertus Bayu Hartanto , Zihao Wu , Yang Zhang , Simone Zoia

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

There is currently a high demand for theoretical predictions for processes at next-to-next-to-leading order (NNLO) and beyond, mainly due to the large amount of data which has already been collected at LHC. This requires practical methods…

High Energy Physics - Theory · Physics 2022-07-06 B. Z. Felippe , A. P. Baêta Scarpelli , A. R. Vieira , J. C. C. Felipe

In this talk we review the GOLEM approach to one-loop calculations and present an automated implementation of this technique. This method is based on Feynman diagrams and an advanced reduction of one-loop tensor integrals which avoids…

We study bilevel optimization problems where the lower-level problems are strongly convex and have coupled linear constraints. To overcome the potential non-smoothness of the hyper-objective and the computational challenges associated with…

Optimization and Control · Mathematics 2026-02-06 Wei Shen , Jiawei Zhang , Minhui Huang , Cong Shen

The success of the experimental program at the Tevatron re-inforced the idea that precision physics at hadron colliders is desirable and, indeed, possible. The Tevatron data strongly suggests that one-loop computations in QCD describe hard…

High Energy Physics - Phenomenology · Physics 2015-05-28 R. Keith Ellis , Zoltan Kunszt , Kirill Melnikov , Giulia Zanderighi

A fast algorithm to study one-dimensional self-gravitating systems, and, more generally, systems that are Lagrangian integrable between collisions, is presented. The algorithm is event-driven, and uses a heap-ordered set of predicted future…

Disordered Systems and Neural Networks · Physics 2007-05-23 Alain Noullez , Duccio Fanelli , Erik Aurell

We present complete analytical ${\mathcal O}(\epsilon^2)$ results on the one-loop amplitudes relevant for the NNLO quark-parton model description of the hadroproduction of heavy quarks as given by the so-called loop-by-loop contributions.…

High Energy Physics - Phenomenology · Physics 2016-08-16 J. G. Körner , Z. Merebashvili , M. Rogal

In this paper we discuss techniques, which lead to a significant improvement of the efficiency of the Monte Carlo integration, when one-loop QCD amplitudes are calculated numerically with the help of the subtraction method and contour…

High Energy Physics - Phenomenology · Physics 2015-06-05 Sebastian Becker , Christian Reuschle , Stefan Weinzierl