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Related papers: Leading-Color Two-Loop QCD Corrections for Three-P…

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We present the analytic calculation of the two-loop QCD corrections to the decay width of a Higgs boson into a photon and a $Z$ boson. The calculation is carried out using integration-by-parts identities for the reduction to master…

High Energy Physics - Phenomenology · Physics 2015-09-30 R. Bonciani , V. Del Duca , H. Frellesvig , J. M. Henn , F. Moriello , V. A. Smirnov

We compute the full set of two-loop Feynman integrals appearing in massless two-loop four-point functions with two off-shell legs with the same invariant mass. These integrals allow to determine the two-loop corrections to the amplitudes…

High Energy Physics - Phenomenology · Physics 2014-06-13 Thomas Gehrmann , Andreas von Manteuffel , Lorenzo Tancredi , Erich Weihs

We compute the two-loop massless QCD corrections to the four-point amplitude $g+g \rightarrow H+H$ resulting from effective operator insertions that describe the interaction of a Higgs boson with gluons in the infinite top quark mass limit.…

High Energy Physics - Phenomenology · Physics 2018-11-30 Pulak Banerjee , Sophia Borowka , Prasanna K. Dhani , Thomas Gehrmann , V. Ravindran

Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes and skewed parton distributions. The determination of the…

High Energy Physics - Phenomenology · Physics 2009-09-25 S. J. Brodsky

We present the gluon-gluon and photon-gluon helicity amplitudes for color singlet and octet charmonium production in polarized and unpolarized hadron-hadron and photon-hadron collisions.

High Energy Physics - Phenomenology · Physics 2008-11-26 M. M. Meijer , J. Smith , W. L. van Neerven

We present a computation of the one-loop QCD corrections to top-quark pair production in association with a $W$ boson, including terms up to order $\varepsilon^2$ in dimensional regularization. Providing a first glimpse into the complexity…

High Energy Physics - Phenomenology · Physics 2025-11-05 Matteo Becchetti , Maximilian Delto , Sara Ditsch , Philipp Alexander Kreer , Mattia Pozzoli , Lorenzo Tancredi

We compute the one-loop QCD amplitudes for the processes HqqQQ and Hqqgg, the latter restricted to the case of opposite-helicity gluons. Analytic expressions are presented for the color- and helicity-decomposed amplitudes. The coupling of…

High Energy Physics - Phenomenology · Physics 2009-12-11 Lance J. Dixon , Yorgos Sofianatos

We present the first explicit formulae for the complete set of one-loop helicity amplitudes necessary for computing next-to-leading order corrections for e^+ e^- annihilation into four jets, for W, Z or Drell-Yan production in association…

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

We study the singularity structure of two-loop QED amplitudes for the production of multiple off-shell photons in massless electron-positron annihilation and develop counterterms that remove their infrared and ultraviolet divergences point…

High Energy Physics - Phenomenology · Physics 2021-04-26 Charalampos Anastasiou , Rayan Haindl , George Sterman , Zhou Yang , Mao Zeng

We report on the fully analytic calculation of the leading-power contribution to the photon-pion transition form factor $\gamma \, \gamma^{\ast} \to \pi^0$ at two loops in QCD. The applied techniques are based on hard-collinear…

High Energy Physics - Phenomenology · Physics 2021-10-29 Jing Gao , Tobias Huber , Yao Ji , Yu-Ming Wang

We accomplish for the first time the two-loop computation of the leading-twist contribution to the pion electromagnetic form factor by employing the effective field theory formalism rigorously. The next-to-next-to-leading-order…

High Energy Physics - Phenomenology · Physics 2024-11-07 Yao Ji , Bo-Xuan Shi , Jian Wang , Ye-Fan Wang , Yu-Ming Wang , Hui-Xin Yu

We investigate the quantum chromodynamics (QCD) corrections to hadronic final states in electron-positron collisions at $\mathcal{O}(\alpha_s^3)$ in the strong coupling constant $\alpha_s$. Namely, we analytically compute the total cross…

High Energy Physics - Phenomenology · Physics 2023-04-24 Petr Jakubčík , Matteo Marcoli , Giovanni Stagnitto

We compute the two-loop QCD corrections to $q g \to H q$ and $q \bar{q} \to H g$ amplitudes mediated by loops of nearly massless quarks. These amplitudes provide the last missing ingredient required to compute the NLO QCD corrections to the…

High Energy Physics - Phenomenology · Physics 2017-03-22 Kirill Melnikov , Lorenzo Tancredi , Christopher Wever

We solve the integration-by-parts (IBP) identities needed for the computation of any planar two-loop five-point massless amplitude in QCD. We also derive some new results for the most complicated non-planar topology with irreducible…

High Energy Physics - Phenomenology · Physics 2019-08-13 Herschel A. Chawdhry , Matthew A. Lim , Alexander Mitov

We discuss recent progress towards extending the Helac framework to the calculation of two-loop amplitudes. A general algorithm for the automated computation of two-loop integrands is described. The algorithm covers all the steps of the…

High Energy Physics - Phenomenology · Physics 2024-01-19 Giuseppe Bevilacqua , Dhimiter Canko , Costas Papadopoulos

We compute the leading color, next-to-leading order QCD corrections to the dominant partonic channels for the production of a W boson in association with three jets at the Tevatron and the LHC. This is the first application of generalized…

High Energy Physics - Phenomenology · Physics 2010-01-07 R. Keith Ellis , Kirill Melnikov , Giulia Zanderighi

We introduce a new color decomposition for multi-parton amplitudes in QCD, free of fundamental-representation matrices and structure constants. This decomposition has a physical interpretation in terms of the flow of color, which makes it…

High Energy Physics - Phenomenology · Physics 2009-11-07 F. Maltoni , K. Paul , T. Stelzer , S. Willenbrock

The numerical unitarity approach has been important for obtaining reliable QCD predictions for the LHC. Here I discuss the extension of the approach beyond the leading quantum corrections for computing multi-loop amplitudes. The numerical…

High Energy Physics - Phenomenology · Physics 2017-03-27 Harald Ita

Processes involving electroweak vector bosons in association with jets are crucial for precision studies of the Standard Model at the Large Hadron Collider. Accurate predictions for the process $pp\rightarrow V(\rightarrow\bar\ell\ell)jj$…

High Energy Physics - Phenomenology · Physics 2024-09-25 Giuseppe De Laurentis

We present a fully analytic calculation of the leading-order one-loop amplitude for triple Higgs production via gluon fusion, $gg \to HHH$, retaining full dependence on the mass of the heavy quark circulating in the loop. This amplitude…

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