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Related papers: Semi-numerical evaluation of one-loop corrections

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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 review techniques simplifying the analytic calculation of one-loop QCD amplitudes with many external legs, for use in next-to-leading-order corrections to multi-jet processes. Particularly useful are the constraints imposed by…

High Energy Physics - Phenomenology · Physics 2016-09-01 Z. Bern , G. Chalmers , L. Dixon , D. C. Dunbar , D. A. Kosower

We present a semi-recursive method for calculating the rational parts of one-loop gravity amplitudes which utilises axial gauge diagrams to determine the non-factorising pieces of the amplitude. This method is used to compute the one-loop…

High Energy Physics - Theory · Physics 2014-11-20 David C. Dunbar , James H. Ettle , Warren B. Perkins

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

We construct a specific formalism for calculating the one-loop virtual corrections for standard model processes with an arbitrary number of external legs. The procedure explicitly separates the infrared and ultraviolet divergences…

High Energy Physics - Phenomenology · Physics 2009-11-10 W. T. Giele , E. W. N. Glover

We present one-loop contributions to the fully differential Higgs boson gluon-fusion cross-section for Higgs production via gluon fusion. Our results constitute a necessary ingredient of a complete N$^3$LO determination of the…

High Energy Physics - Phenomenology · Physics 2019-06-05 Charalampos Anastasiou , Caterina Specchia

We obtain the two-loop QCD corrections to the Higgs plus three-parton amplitudes with dimension-seven operators in Higgs effective field theory. This provides the two-loop S-matrix elements for Higgs plus one-jet production at the LHC with…

High Energy Physics - Phenomenology · Physics 2020-03-18 Qingjun Jin , Gang Yang

In the very near future the first data from LHC will be available. The searches for the Higgs boson and for new physics will require precise predictions both for the signal and the background processes. Tree level calculations typically…

High Energy Physics - Phenomenology · Physics 2009-03-06 Thomas Reiter

We present a completely numerical method of calculating one-loop amplitudes. Our approach is built upon two different existing methods: the contour deformation and the extrapolation methods. Taking the best features of each of them, we…

High Energy Physics - Phenomenology · Physics 2017-02-01 Goran Duplancic , Bruno Klajn

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 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 compute the one-loop amplitude for a Higgs boson, a quark-antiquark pair and a pair of gluons of negative helicity, i.e. for the next-to-maximally helicity violating (NMHV) case, A(H, qbar-, q+, g-, g-). The calculation is performed…

High Energy Physics - Phenomenology · Physics 2009-12-17 Simon Badger , John M. Campbell , R. Keith Ellis , Ciaran Williams

We present for the first time the second-order corrections of pseudo-scalar($A$) Higgs decay to three parton to higher orders in the dimensional regulator. We compute the one and two-loop amplitudes for processes, $A\to ggg$ and $A\to…

High Energy Physics - Phenomenology · Physics 2026-01-30 Pulak Banerjee , Chinmoy Dey , M. C. Kumar , V. Ravindran

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

We compute the contribution of three-loop mixed QCD-electroweak corrections ($\alpha_S^2\alpha^2$) to the $gg \to H$ scattering amplitude. We employ the method of differential equations to compute the relevant integrals and express them in…

High Energy Physics - Phenomenology · Physics 2018-05-10 Marco Bonetti , Kirill Melnikov , Lorenzo Tancredi

Recent progress in unitarity techniques for one-loop scattering amplitudes makes a numerical implementation of this method possible. We present a 4-dimensional unitarity method for calculating the cut-constructible part of amplitudes and…

High Energy Physics - Phenomenology · Physics 2009-09-17 R. K. Ellis , W. T. Giele , Z. Kunszt

We review recent developments in the calculation of QCD loop amplitudes with several external legs, and their application to next-to-leading order jet production cross-sections. When a number of calculational tools are combined together ---…

High Energy Physics - Phenomenology · Physics 2007-05-23 Z. Bern , L. Dixon , D. A. Kosower , A. Signer

We compute the two-loop massless QCD corrections to the amplitude of Higgs boson decay to bottom quark pair and a gluon ($H \rightarrow b + \bar{b} + g$) in the higher powers of the dimensional regularization parameter $\epsilon$. The…

High Energy Physics - Phenomenology · Physics 2026-05-28 Pulak Banerjee , Chinmoy Dey , M. C. Kumar , Vaibhav Pandey , V. Ravindran

An approach for an effective computer evaluation of one-loop multi-leg diagrams is proposed. It's main feature is the combined use of several systems - DIANA, FORM and MAPLE. As an application we consider the one-loop correction to Higgs…

High Energy Physics - Phenomenology · Physics 2009-11-07 F. Jegerlehner , O. Tarasov

We compute the complete two-loop electroweak corrections to the Higgsstralung process $e^+e^-\rightarrow HZ$ at the future Higgs factory. The Feynman integrals involved in the computation are decomposed into linear combinations of a minimal…

High Energy Physics - Phenomenology · Physics 2023-07-12 Xiang Chen , Xin Guan , Chuan-Qi He , Zhao Li , Xiao Liu , Yan-Qing Ma