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We present a calculation of O(\alpha_s) contributions to the process of t-channel single-top production and decay, which include virtual and real corrections arising from interference of the production and decay subprocesses. The…

High Energy Physics - Phenomenology · Physics 2014-11-21 Pietro Falgari , Paul Mellor , Adrian Signer

The factorisation of QCD matrix elements in the limit of two external partons becoming collinear is described by process-independent splitting amplitudes, which can be expanded systematically in perturbation theory. Working in conventional…

High Energy Physics - Phenomenology · Physics 2015-06-23 Claude Duhr , Thomas Gehrmann , Matthieu Jaquier

We compute a complete set of independent leading-color two-loop five-parton amplitudes in QCD. These constitute a fundamental ingredient for the next-to-next-to-leading order QCD corrections to three-jet production at hadron colliders. We…

High Energy Physics - Phenomenology · Physics 2019-04-09 S. Abreu , F. Febres Cordero , H. Ita , B. Page , V. Sotnikov

We present the analytic calculation of the Master Integrals for the two-loop, non-planar topologies that enter the calculation of the amplitude for top-quark pair hadroproduction in the quark-annihilation channel. Using the method of…

High Energy Physics - Phenomenology · Physics 2019-09-04 Matteo Becchetti , Roberto Bonciani , Valerio Casconi , Andrea Ferroglia , Simone Lavacca , Andreas von Manteuffel

We present the master integrals relevant for computing the complete set of leading-colour analytic helicity amplitudes for top-quark pair production via gluon fusion at two-loops in QCD. We include corrections due to massive fermion loops…

High Energy Physics - Phenomenology · Physics 2021-11-01 Ekta Chaubey

We compute two-loop helicity amplitudes in QCD for diphoton production through quark- and gluon-initiated channels, accounting for a massive internal quark loop by keeping its full mass dependence. Using physical projectors, we directly…

High Energy Physics - Phenomenology · Physics 2025-02-06 Taushif Ahmed , Amlan Chakraborty , Ekta Chaubey , Mandeep Kaur

We compute mixed QCD-weak corrections to inclusive Higgs production at the LHC from the partonic process $g g \rightarrow H q \bar{q}$. We start from the UV- and IR-finite one-loop weak amplitude and consider its interference with the…

High Energy Physics - Phenomenology · Physics 2019-05-22 Valentin Hirschi , Simone Lionetti , Armin Schweitzer

We report on the calculation of the factorisable one-loop weak-interaction corrections to the initial and final states for three-jet observables in electron-positron annihilations. We show that such corrections are of a few percent at…

High Energy Physics - Phenomenology · Physics 2011-07-19 E. Maina , S. Moretti , D. A. Ross

Recent progress in our understanding of infrared singularities of multi-parton amplitudes has shown that the simplest form of Regge factorization for high-energy gauge-theory amplitudes fails starting at next-to-next-to-leading logarithmic…

High Energy Physics - Phenomenology · Physics 2015-06-17 Vittorio Del Duca , Giulio Falcioni , Lorenzo Magnea , Leonardo Vernazza

We compute helicity amplitudes for the one-loop QCD corrections to top-quark pair production analytically in terms of a set of uniformly transcendental master integrals. We provide corrections up to $O(\epsilon^2)$ in the dimensional…

High Energy Physics - Phenomenology · Physics 2022-06-29 Simon Badger , Matteo Becchetti , Ekta Chaubey , Robin Marzucca , Francesco Sarandrea

We evaluate non factorizable $O(\alpha\alpha_s)$ corrections to the process $Z\to b\bar{b}$ due to the virtual t-quark. All two-loop vertex diagrams with $W$'s and charged ghosts $\Phi$'s are included. They are evaluated in the large…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. Fleischer , F. Jegerlehner , M. Tentyukov , O. Veretin

The non-first-order-factorizable contributions (The terms 'first-order-factorizable contributions' and 'non-first-order-factorizable contributions' have been introduced and discussed in Refs. \cite{Behring:2023rlq,Ablinger:2023ahe}. They…

High Energy Physics - Phenomenology · Physics 2024-05-15 J. Ablinger , A. Behring , J. Blümlein , A. De Freitas , A. von Manteuffel , C. Schneider , K. Schönwald

The ability to calculate analytic full-colour two-to-three two-loop helicity amplitudes in massless QCD has been a recent triumph of the field, driving phenomenology towards one percent precision. In this contribution, we focus on the…

High Energy Physics - Phenomenology · Physics 2023-10-31 Ryan Moodie

We compute the helicity amplitudes for the processes $gg\to Zg$ and $gg\to Z\gamma$ to two loops in massless QCD. The perturbative expansion of these processes starts only at the one-loop level, such that our results are a crucial…

High Energy Physics - Phenomenology · Physics 2023-08-21 Thomas Gehrmann , Lorenzo Tancredi , Erich Weihs

The computation of two-loop amplitudes for the production of multiple Higgs and electroweak gauge bosons via gluon fusion with exact dependence on quark masses relies primarily on numerical methods. We propose a framework that enables their…

High Energy Physics - Phenomenology · Physics 2024-11-13 Charalampos Anastasiou , Julia Karlen , George Sterman , Aniruddha Venkata

We present results for the production of a pair of on-shell Z bosons via gluon fusion. This process occurs both through the production and decay of the Higgs boson, and through continuum production where the Z boson couples to a loop of…

High Energy Physics - Phenomenology · Physics 2016-08-09 John M. Campbell , R. Keith Ellis , Michal Czakon , Sebastian Kirchner

We compute the two-loop Quantum Chromodynamics (QCD) corrections to all partonic channels relevant for the production of an electroweak boson $V=Z,W^\pm,\gamma^*$ and a jet at hadron colliders. We consider the decay of a vector boson $V$ to…

High Energy Physics - Phenomenology · Physics 2023-06-21 Thomas Gehrmann , Petr Jakubčík , Cesare Carlo Mella , Nikolaos Syrrakos , Lorenzo Tancredi

We present analytic expressions for the one-loop QCD helicity amplitudes contributing to top-quark pair production in association with a photon or a jet at the Large Hadron Collider (LHC), evaluated through $\mathcal{O}(\epsilon^2)$ in the…

High Energy Physics - Phenomenology · Physics 2026-05-15 Souvik Bera , Colomba Brancaccio , Dhimiter Canko , Heribertus Bayu Hartanto

We highlight the latest developments in computing higher-order scattering amplitudes with massive internal propagators. The contributing Feynman integrals often lead to special classes of functions, for example, functions associated with…

High Energy Physics - Phenomenology · Physics 2022-07-26 Ekta Chaubey

We present a method for the integrand-level reduction of two-loop helicity amplitudes in both $d=4-2\epsilon$ and $d=4$ dimensions. The amplitude is expressed in terms of a set of Feynman integrals and their coefficients that depend on the…

High Energy Physics - Phenomenology · Physics 2025-11-14 Giuseppe Bevilacqua , Dhimiter Canko , Costas Papadopoulos , Aris Spourdalakis