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Related papers: Automated One-Loop Calculations with GoSam

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We report on the two-loop amplitude computation for the mixed QCD-electroweak corrections to the process $gg \to Hg$, with exact dependence on the electroweak boson masses. This amplitude has been employed in the computation of…

High Energy Physics - Phenomenology · Physics 2022-05-11 Matteo Becchetti , Francesco Moriello , Armin Schweitzer

In the context of constructing one-loop amplitudes using a unitarity bootstrap approach we discuss a general systematic procedure for obtaining the coefficients of the scalar bubble and triangle integral functions of one-loop amplitudes.…

High Energy Physics - Phenomenology · Physics 2009-08-07 Darren Forde

We discuss two-loop leading and angular-dependent next-to-leading logarithmic electroweak virtual corrections to arbitrary processes at energies above the electroweak scale. The relevant Feynman diagrams involving soft-collinear gauge…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ansgar Denner , Michael Melles , Stefano Pozzorini

We present the computer code RECOLA for the computation of EW and QCD amplitudes in the Standard Model at next-to-leading order. One-loop amplitudes are represented as linear combinations of tensor integrals whose coefficients are…

High Energy Physics - Phenomenology · Physics 2013-11-27 Stefano Actis , Ansgar Denner , Lars Hofer , Andreas Scharf , Sandro Uccirati

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

As the new-generation precision experiments such as MOLLER and P2 look for physics beyond Standard Model, it is becoming increasingly important to evaluate the higher-order electroweak radiative corrections to a sub-percent level of…

High Energy Physics - Theory · Physics 2019-12-11 A. Aleksejevs , S. Barkanova

We extend the generalized D-dimensional unitarity method for numerical evaluation of one-loop amplitudes by incorporating massive particles. The issues related to extending the spinor algebra to higher dimensions, treatment of external…

High Energy Physics - Phenomenology · Physics 2010-04-21 R. K. Ellis , W. T. Giele , Z. Kunszt , K. Melnikov

A program package, which facilitates computations in the framework of Analytic approach to QCD, is developed and described in details. The package includes the explicit expressions for relevant spectral functions calculated up to the…

High Energy Physics - Phenomenology · Physics 2014-11-20 A. V. Nesterenko , C. Simolo

We present the program package ggxy, which in its first version can be used to calculate partonic and hadronic cross sections to Higgs boson pair production at NLO QCD and it offers a direct interface to POWHEG-BOX. The 2-loop virtual…

High Energy Physics - Phenomenology · Physics 2025-12-19 Daniel Stremmer

Modelling non-linear activation functions on quantum computers is vital for quantum neurons employed in fully quantum neural networks, however, remains a challenging task. We introduce an amplitude-based implementation for approximating…

Quantum Physics · Physics 2023-02-09 Jonas Koppe , Mark-Oliver Wolf

Higher order corrections in perturbative quantum field theory are required for precise theoretical analysis to investigate new physics beyond the Standard Model. This indicates that we need to evaluate Feynman loop diagram with multi-loop…

High Energy Physics - Phenomenology · Physics 2014-12-02 Shinji Motoki , Hiroshi Daisaka , Naohito Nakasato , Tadashi Ishikawa , Fukuko Yuasa , Toshiyuki Fukushige , Atsushi Kawai , Junichiro Makino

The direct computation method(DCM) is developed to calculate the multi-loop amplitude for general masses and external momenta. The ultraviolet divergence is under control in dimensional regularization. In this paper we report on the…

High Energy Physics - Phenomenology · Physics 2018-03-15 K Kato , E de Doncker , T Ishikawa , F Yuasa

aITALC, a new tool for automating loop calculations in high energy physics, is described. The package creates Fortran code for two-fermion scattering processes automatically, starting from the generation and analysis of the Feynman graphs.…

High Energy Physics - Phenomenology · Physics 2009-11-10 Alejandro Lorca , Tord Riemann

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

Feynman diagrams may be evaluated by Mellin-Barnes representations of their Feynman parameter integrals in d=4-2\eps dimensions. Recently, the Mathematica toolkit AMBRE has been developed for the automatic derivation of such representations…

High Energy Physics - Phenomenology · Physics 2009-04-16 J. Gluza , F. Haas , K. Kajda , T. Riemann

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

We review progress in calculating one-loop scattering amplitudes required for next-to-leading-order corrections to QCD processes. The underlying technical developments include the spinor helicity formalism, color decompositions,…

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

A simple algorithm is presented to decompose any 1-loop amplitude for scattering processes of the class 2 fermions -> 4 fermions into a fixed number of gauge-invariant form factors. The structure of the amplitude is simpler than in the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Alessandro Vicini

An algorithm for the reduction of one-loop n-point tensor integrals to basic integrals is proposed. We transform tensor integrals to scalar integrals with shifted dimension and reduce these by recurrence relations to integrals in generic…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Fleischer , F. Jegerlehner , O. V. Tarasov

A unified formulation of one-loop tensor integrals is proposed for systematical calculations of finite volume corrections. It is shown that decomposition of the one-loop tensor integrals into a series of tensors accompanied by tensor…

High Energy Physics - Phenomenology · Physics 2022-12-28 Ze-Rui Liang , De-Liang Yao