English
Related papers

Related papers: Semi-Numerical Evaluation of One-Loop Corrections

200 papers

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

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

We explain how one-loop amplitudes with massive fermions can be computed using only on-shell information. We first use the spinor-helicity formalism in six dimensions to perform generalised unitarity cuts in $d$ dimensions. We then show…

High Energy Physics - Phenomenology · Physics 2017-08-02 Simon Badger , Christian Brønnum-Hansen , Francesco Buciuni , Donal O'Connell

We propose that loop integrals with internal heavy particles can be evaluated by expanding in the limit of small external masses. This provides a systematically improvable approximation to the integrals in the entire phase space, and works…

High Energy Physics - Phenomenology · Physics 2019-02-05 Xiaofeng Xu , Li Lin Yang

We describe a new method for the automated construction of one-loop amplitudes based on the open-loop algorithm, where various operations are performed on-the-fly while constructing the integrand. In particular, an on-the-fly reduction…

High Energy Physics - Phenomenology · Physics 2018-01-12 Federico Buccioni , Stefano Pozzorini , Max Zoller

A new scheme for the numerical evaluation of the one-loop self-energy correction to all orders in Z \alpha is presented. The scheme proposed inherits the attractive features of the standard potential-expansion method but yields a…

Atomic Physics · Physics 2009-11-11 Vladimir A. Yerokhin , Krzysztof Pachucki , Vladimir M. Shabaev

In this paper we compute the the one-loop chiral logarithmic corrections to the S and T parameters in a highly deconstructed Higgsless model with only three sites. In addition to the electroweak gauge bosons, this model contains a single…

High Energy Physics - Phenomenology · Physics 2008-11-26 Shinya Matsuzaki , R. Sekhar Chivukula , Elizabeth H. Simmons , Masaharu Tanabashi

We present an optimization of the reduction algorithm of one-loop amplitudes in terms of master integrals. It is based on the exploitation of the polynomial structure of the integrand when evaluated at values of the loop-momentum fulfilling…

High Energy Physics - Phenomenology · Physics 2008-11-26 P. Mastrolia , G. Ossola , C. G. Papadopoulos , R. Pittau

Small-scale scalar perturbations amplified during inflation can induce primordial gravitational waves through tensor-scalar interactions. A long-standing controversial issue is whether the one-loop corrections to tensor perturbations exist…

General Relativity and Quantum Cosmology · Physics 2025-09-03 Cheng-Jun Fang , Han-Wen Hu , Zong-Kuan Guo

Reference [1] introduces a method for computing numerically four-dimensional multi-loop integrals without performing an explicit analytic contour deformation around threshold singularities. In this paper, we extend such a technique to…

High Energy Physics - Phenomenology · Physics 2024-07-26 Roberto Pittau

We present methods to compute higher orders in the threshold expansion for the one-loop production of a Higgs boson in association with two partons at hadron colliders. This process contributes to the N$^3$LO Higgs production cross section…

High Energy Physics - Phenomenology · Physics 2015-09-30 Charalampos Anastasiou , Claude Duhr , Falko Dulat , Elisabetta Furlan , Franz Herzog , Bernhard Mistlberger

This note reports on an independent implementation of calculating one-loop amplitudes semi-numerically using generalized unitarity techniques. The algorithm implemented in form of a C++ code closely follows the method by Ellis, Giele,…

High Energy Physics - Phenomenology · Physics 2009-02-03 Jan-Christopher Winter , Walter T. Giele

Modern particle physics is increasingly becoming a precision science that relies on advanced theoretical predictions for the analysis and interpretation of experimental results. The planned physics program at the LHC and future colliders…

High Energy Physics - Phenomenology · Physics 2023-01-04 Ievgen Dubovyk , Ayres Freitas , Janusz Gluza , Krzysztof Grzanka , Martijn Hidding , Johann Usovitsch

We report on the advances in the calculation of the two-loop scattering amplitudes for five-particle processes with one off-shell leg. Focusing on the production of a Higgs boson in association with a bottom quark pair, we outline how the…

High Energy Physics - Phenomenology · Physics 2023-03-01 Jakub Kryś

A new method for the reduction of one-loop tensor 5-point integrals to related 4-point integrals is proposed. In contrast to the usual Passarino-Veltman reduction and other methods used in the literature, this reduction avoids the…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Denner , S. Dittmaier

In this paper, I present a technique to simplify the tensorial reduction of one-loop integrals with arbitrary internal masses, but at least two massless external legs. By applying the method to rank l tensor integrals, one ends up with at…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. Pittau

In this work we consider numerical efficiency and convergence rates for solvers of non-convex multi-penalty formulations when reconstructing sparse signals from noisy linear measurements. We extend an existing approach, based on reduction…

Information Theory · Computer Science 2021-01-15 Zeljko Kereta , Johannes Maly , Valeriya Naumova

We propose a new method to calculate analytically higher-order perturbative corrections and we apply it to the calculation of the two-loop virtual corrections to Higgs pair production through gluon fusion. The method is based on the…

High Energy Physics - Phenomenology · Physics 2018-11-26 Roberto Bonciani , Giuseppe Degrassi , Pier Paolo Giardino , Ramona Gröber

We study one-loop effects of sfermions on helicity amplitudes for $\eeww$ in the Minimal Supersymmetric Standard Model. The one-loop contributions are calculated in the $\bar{\rm MS}$ renormalization scheme. In order to verify the validity…

High Energy Physics - Phenomenology · Physics 2009-10-31 Sher Alam , Kaoru Hagiwara , Shinya Kanemura , Robert Szalapski , Yoshiaki Umeda

We present a new systematic method to evaluate one-loop tensor integrals in conventional ultraviolet cutoff regularization. By deriving a new recursive relation that describes the momentum translation variance of ultraviolet integrals, we…

High Energy Physics - Phenomenology · Physics 2015-06-03 Hua-Sheng Shao , Yu-Jie Zhang , Kuang-Ta Chao