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Related papers: Two-Loop Four-Fermion Scattering Amplitude in QED

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We consider reduced quantum electrodynamics (RQED$_{d_\gamma,d_e}$) a model describing fermions in a $d_e$-dimensional space-time and interacting via the exchange of massless bosons in $d_\gamma$-dimensions ($d_e \leq d_\gamma$). We compute…

High Energy Physics - Theory · Physics 2021-10-08 S. Metayer , S. Teber

I discuss the status of the computation of the two-loop QCD corrections to top-quark pair production associated with a jet at hadron colliders. This amplitude is a missing ingredient for next-to-next-to-leading order (NNLO) QCD predictions.…

High Energy Physics - Phenomenology · Physics 2024-11-19 Colomba Brancaccio

Multi-loop scattering amplitudes constitute a serious bottleneck in current high-energy physics computations. Obtaining new integrand level representations with smooth behaviour is crucial for solving this issue, and surpassing the…

High Energy Physics - Phenomenology · Physics 2021-09-17 German F. R. Sborlini

We derive logarithmically enhanced two-loop virtual electroweak corrections for arbitrary fermion-scattering processes at the TeV scale. This extends results previously obtained for massless fermion scattering to processes that involve also…

High Energy Physics - Phenomenology · Physics 2009-11-19 Ansgar Denner , Bernd Jantzen , Stefano Pozzorini

We evaluate, in the high-energy limit, $s\gg|t|\gg m^2\gg\lambda^2$, the sum of amplitudes corresponding to a class of Feynman diagrams describing two-loop virtual photonic corrections to Bhabha scattering. The diagrams considered are box…

High Energy Physics - Phenomenology · Physics 2009-10-22 Göran Fäldt , Per Osland

We compute the eighth-order fermionic corrections involving two and three closed massless fermion loops to the anomalous magnetic moment of the muon. The required four-loop on-shell integrals are classified and explicit analytical results…

High Energy Physics - Phenomenology · Physics 2015-06-12 Roman Lee , Peter Marquard , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We compute the full three-loop coefficient functions for the structure functions F_2 and F_L in massless perturbative QCD. The results for F_L complete the next-to-next-to-leading order description of unpolarized electromagnetic…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. A. M. Vermaseren , A. Vogt , S. Moch

We consider two-loop leading and next-to-leading logarithmic virtual corrections to arbitrary processes with external massless fermions in the electroweak Standard Model at energies well above the electroweak scale. Using the…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Denner , B. Jantzen , S. Pozzorini

We introduce Scale Factorized-Quantum Field Theory (SF-QFT), a framework performing path-integral factorization of ultraviolet and infrared momentum modes at a physical scale $Q^*$ before perturbative expansion through Effective Dynamical…

High Energy Physics - Phenomenology · Physics 2026-03-23 Farrukh A. Chishtie

We discuss recent results for the asymptotic behavior of fermion scattering amplitudes in the Sudakov limit. The results include next-to-next-to-leading logarithmic electroweak corrections and are used for the analysis of…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. Moch

We present a description of calculations of the amplitude for E+ E- --> F anti-F process with account of electroweak and QED one-loop corrections. This study is performed within the framework of the project SANC. The calculations are done…

High Energy Physics - Phenomenology · Physics 2011-01-13 A. Andonov , D. Bardin , S. Bondarenko , P. Christova , L. Kalinovskaya , G. Nanava

We evaluate the fermionic two-loop QCD corrections to the heavy-quark pair production process in the quark-antiquark channel. We obtain analytic results which are valid for any value of the Mandelstam invariants s and t, and of the heavy…

High Energy Physics - Phenomenology · Physics 2009-11-13 R. Bonciani , A. Ferroglia , T. Gehrmann , D. Maitre , C. Studerus

We discuss a mapping of lattice QED with two flavors and a chemical potential to dual variables, which are surfaces for the gauge fields and loops for the fermions. The gauge fields are completely dualized and the corresponding dual…

High Energy Physics - Lattice · Physics 2015-02-10 Michael Kniely , Christof Gattringer

The two-loop massive operator matrix elements for the fermionic local twist--2 operators with external massive fermion lines in Quantum Electrodynamics (QED) are calculated up to the constant terms in the dimensional parameter $\epsilon = D…

High Energy Physics - Phenomenology · Physics 2011-11-02 Johannes Blümlein , Abilio De Freitas , Wilhelmus van Neerven

We present the two-loop virtual QCD corrections to the scattering of massless identical quarks, q qbar to q qbar, in conventional dimensional regularisation and using the MSbar scheme. The structure of the infrared divergences agrees with…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. Anastasiou , E. W. N. Glover , C. Oleari , M. E. Tejeda-Yeomans

We use the solutions to the recursion relations for double-off-shell fermion currents to compute helicity amplitudes for $n$-photon scattering and electron-positron annihilation to photons in the massless limit of QED. The form of these…

High Energy Physics - Phenomenology · Physics 2009-10-22 Gregory Mahlon

The calculation of hard scattering amplitudes up to NLO is automated in numerical tools, such as OpenLoops. The LHC and future experiments, however, demand high-precision predictions at NNLO and beyond for a wide range of particle…

High Energy Physics - Phenomenology · Physics 2024-12-20 Natalie Schär , Max F. Zoller

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

The infrared exponentiation properties of dimensionally-regularized multi-loop scattering amplitudes are typically hidden at the level of the integrand, materializing only after integral evaluation. We address this long-standing problem by…

High Energy Physics - Theory · Physics 2019-07-22 Robert M. Schabinger

The two-loop (Euler-Heisenberg-type) effective action for N = 2 supersymmetric QED is computed using the N = 1 superspace formulation. The effective action is expressed as a series in supersymmetric extensions of F^{2n}, where n=2,3,...,…

High Energy Physics - Theory · Physics 2009-11-10 S. M. Kuzenko , I. N. McArthur