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Related papers: Fermionic NNLO contributions to Bhabha scattering

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We evaluate the two-loop corrections to Bhabha scattering from fermion loops in the context of pure Quantum Electrodynamics. The differential cross section is expressed by a small number of Master Integrals with exact dependence on the…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Actis , M. Czakon , J. Gluza , T. Riemann

We describe in detail the calculation of the two-loop corrections to the QED Bhabha scattering cross section due to the vacuum polarization by heavy fermions. Our approach eliminates one mass scale from the most challenging part of the…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Bonciani , A. Ferroglia , A. A. Penin

Virtual hadronic contributions to the Bhabha process at the NNLO level are discussed. They are substantial for predictions with per mil accuracy. The studies of heavy fermion and hadron corrections complete the calculation of Bhabha virtual…

High Energy Physics - Phenomenology · Physics 2008-11-26 Stefano Actis , Janusz Gluza , Tord Riemann

Theoretical predictions for Bhabha scattering at the two-loop level require the inclusion of hadronic vacuum polarization in the photon propagator. We present predictions for the contributions from reducible amplitudes which are…

High Energy Physics - Phenomenology · Physics 2008-11-26 Johann H. Kühn , Sandro Uccirati

Effects of vacuum polarization by hadronic and heavy-fermion insertions were the last unknown two-loop QED corrections to high-energy Bhabha scattering and have been first announced in \cite{Actis:2007fs}. Here we describe the corrections…

High Energy Physics - Phenomenology · Physics 2008-11-26 Stefano Actis , Michal Czakon , Janusz Gluza , Tord Riemann

Virtual fermionic N_f = 1 and N_f = 2 contributions to Bhabha scattering are combined with realistic real corrections at next-to-next-to-leading order in QED. The virtual corrections are determined by the package bha_nnlo_hf, and real…

High Energy Physics - Phenomenology · Physics 2015-05-28 C. Carloni Calame , H. Czyz , J. Gluza , M. Gunia , G. Montagna , O. Nicrosini , F. Piccinini , T. Riemann , M. Worek

We review the status of the calculation of next-to-next-to-leading order corrections to large angle Bhabha scattering in pure QED. After discussing the electron-loop and photonic corrections, we focus on the recently calculated two-loop…

High Energy Physics - Phenomenology · Physics 2008-11-07 R. Bonciani , A. Ferroglia

We evaluate the two-loop QED corrections to the Bhabha scattering cross section which involve the vacuum polarization by heavy fermions of arbitrary mass m_f >> m_e. The results are valid for generic values of the Mandelstam invariants…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Bonciani , A. Ferroglia , A. A. Penin

Using dispersion relations, we derive the complete virtual QED contributions to Bhabha scattering due to vacuum polarization effects in photon propagation. We apply our result to hadronic corrections and to heavy lepton and top quark loop…

High Energy Physics - Phenomenology · Physics 2008-11-26 Stefano Actis , Michal Czakon , Janusz Gluza , Tord Riemann

We briefly review the status of the calculation of next-to-next-to-leading order corrections to large angle Bhabha scattering in pure QED. In particular, we focus on the analytic calculation of the two-loop virtual corrections involving a…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Bonciani , A. Ferroglia

The two-loop radiative photonic corrections to the Bhabha scattering are computed in the leading order of the small electron mass expansion up to nonlogarithmic term. After including the soft photon bremsstrahlung we obtain the infrared…

High Energy Physics - Phenomenology · Physics 2009-11-11 A. A. Penin

We present the first calculation of the complete set of NNLO QED corrections for muon-electron scattering. This includes leptonic, non-perturbative hadronic, and photonic contributions. All fermionic corrections as well as the photonic…

High Energy Physics - Phenomenology · Physics 2023-02-08 A. Broggio , T. Engel , A. Ferroglia , M. K. Mandal , P. Mastrolia , M. Rocco , J. Ronca , A. Signer , W. J. Torres Bobadilla , Y. Ulrich , M. Zoller

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

Recent developments in the computation of two-loop master integrals for massive Bhabha scattering are briefly reviewed. We apply a method based on expansions of exact Mellin-Barnes representations and evaluate all planar four-point master…

High Energy Physics - Phenomenology · Physics 2009-11-11 Stefano Actis , Michal Czakon , Janusz Gluza , Tord Riemann

The method for obtaining functional equations, recently proposed by one of the authors, is applied to one-loop box integrals needed in calculations of radiative corrections to heavy-quark production and Bhabha scattering. We present…

High Energy Physics - Phenomenology · Physics 2009-07-22 Bernd A. Kniehl , Oleg V. Tarasov

We revisit the contributions of order $\alpha^2(Z\alpha)^5m$ and $\alpha^2(Z\alpha)E_F$, respectively, to the Lamb shift and to the hyperfine splitting from mixed self-energy-vacuum-polarization diagrams, involving fermionic loop. We use…

High Energy Physics - Phenomenology · Physics 2023-08-16 Petr A. Krachkov , Roman N. Lee

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 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 cross-section of (quasi-)elastic large-angle electron-positron scattering at high energies is calculated. Radiative corrections of the orders O(\alpha^2 L^2) and O(\alpha^2 L), besides pure two-loop box contributions, are explicitly…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. B. Arbuzov , E. A. Kuraev , B. G. Shaikhatdenov

Masses of heavy Standard Model fermions (top-quark, bottom-quark, and tau-lepton) play an important role in the analysis of theories beyond the SM. They serve as low-energy input and reduce the parameter space of such theories. In this…

High Energy Physics - Phenomenology · Physics 2010-05-25 A. V. Bednyakov
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