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Related papers: Towards W b bbar + j at NLO with an automatized ap…

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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

We evaluate the complete four-loop anomalous dimension matrix that is necessary for determining the effective flavour-changing neutral current couplings qbar-q'-gamma and qbar-q'-g at the next-to-next-to-leading order in QCD. The resulting…

High Energy Physics - Phenomenology · Physics 2010-10-27 Michal Czakon , Ulrich Haisch , Mikolaj Misiak

We present the first analytic results of N$^3$LO QCD corrections to the top-quark decay width. We focus on the dominant leading color contribution, which includes light-quark loops. At NNLO, this dominant contribution accounts for 95% of…

High Energy Physics - Phenomenology · Physics 2024-04-26 Long-Bin Chen , Hai Tao Li , Zhao Li , Jian Wang , Yefan Wang , Quan-feng Wu

For Z -> b bbar, we calculate all the two-loop top dependent Feynman graphs, which have mixed QCD and electroweak contributions that are not factorizable. For evaluating the graphs, without resorting to a mass expansion, we apply a two-loop…

High Energy Physics - Phenomenology · Physics 2009-10-31 Adrian Ghinculov , York-Peng Yao

We complete the computation of two-loop helicity amplitudes required to obtain next-to-next-to-leading order QCD corrections for three-jet production at hadron colliders, including all contributions beyond the leading-color approximation.…

High Energy Physics - Phenomenology · Physics 2024-05-15 Giuseppe De Laurentis , Harald Ita , Vasily Sotnikov

NLO scattering amplitudes are provided by fully automated numerical tools, such as OpenLoops, for a very wide range of processes. In order to match the numerical precision of current and future collider experiments, the higher precision of…

High Energy Physics - Phenomenology · Physics 2022-07-18 Stefano Pozzorini , Natalie Schär , Max F. Zoller

We compute the next-to-leading order (NLO) QCD corrections to the $gg \to W^+ W^- \to l^+_1 \nu_1 l^-_2 \bar \nu_2$ process, mediated by a massless quark loop, at the LHC. This process first contributes to the hadroproduction of $W^+W^-$ at…

High Energy Physics - Phenomenology · Physics 2016-01-27 Fabrizio Caola , Kirill Melnikov , Raoul Röntsch , Lorenzo Tancredi

We perform a complete calculation of the next-to-next-to-leading order (NNLO) electroweak fermionic corrections to fermion-pair production processes, where "fermionic" refers to contributions with closed fermion loops. We did this via a…

High Energy Physics - Phenomenology · Physics 2026-05-26 Ayres Freitas , E. Jackson Wallace

The computation of one-loop corrections to the $\gamma^\star Q_+ q$ and $gR_+g$ effective vertices in the framework of gauge-invariant effective theory for Multi-Regge processes in QCD is reviewed. Due to consistent implementation of the…

High Energy Physics - Phenomenology · Physics 2019-05-29 Maxim Nefedov

I present a unified approach to calculating the next-to-next-to-leading order (NNLO) soft and virtual QCD corrections to cross sections for electroweak, Higgs, QCD, and SUSY processes. I derive master formulas that can be used for any of…

High Energy Physics - Phenomenology · Physics 2009-11-10 Nikolaos Kidonakis

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

We report on a recent calculation of the two-loop virtual QCD corrections to the W boson pair production in the quark-anti-quark-annihilation channel in the limit where all kinematical invariants are large compared to the mass of the W…

High Energy Physics - Phenomenology · Physics 2008-12-30 Grigorios Chachamis

We employ the recently developed method of generalized $D$-dimensional unitarity to compute one-loop virtual corrections to all scattering amplitudes relevant for the production of a $W$ boson in association with three jets in hadronic…

High Energy Physics - Phenomenology · Physics 2009-02-12 R. Keith Ellis , W. T. Giele , Zoltan Kunszt , Kirill Melnikov , Giulia Zanderighi

The next-to-leading order (NLO) QCD corrections to top anti-top bottom anti-bottom (tTbB) production at the LHC reveal that the scale choice adopted in previous lowest-order simulations underestimates the tTbB cross section by a factor two.…

High Energy Physics - Phenomenology · Physics 2018-08-09 Axel Bredenstein , Ansgar Denner , Stefan Dittmaier , Stefano Pozzorini

QCD one-loop corrections to the full gauge invariant set of electroweak diagrams describing the hadronic process $e^+ e^- \to u~\bar d~s~\bar c$ are computed. Four-jet shape variables for $WW$ events are studied at next-to-leading order and…

High Energy Physics - Phenomenology · Physics 2011-02-01 E. Maina , R. Pittau , M. Pizzio

We outline the computational details to obtain mixed EW-QCD corrections to on-shell production of a single vector boson at the LHC at two-loop level. We use the method of differential equation to obtain the pure virtual, real-virtual and…

High Energy Physics - Phenomenology · Physics 2019-12-24 Roberto Bonciani , Federico Buccioni , Narayan Rana , Alessandro Vicini

We compute the imaginary part of the 2-loop vertex corrections in the QCD Factorization framework for hadronic two-body decays as B -> pi pi. This completes the NNLO calculation of the imaginary part of the topological tree amplitudes and…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guido Bell

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…

We study the full contributions at the leading order(LO) and QCD next-to-leading order(NLO) to the cross section of the \eewwbb process in the standard model(SM) at the ILC. In dealing the resonance problem we adopted the complex mass…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guo Lei , Ma Wen-Gan , Zhang Ren-You , Wang Shao-Ming

We present the one-loop QCD amplitudes for two external massless quarks and three external gluons ($\bar{q}qggg$). This completes the set of one-loop amplitudes needed for the next-to-leading-order corrections to three-jet production at…

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