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Related papers: Two-Loop Electroweak Corrections with Fermion Loop…

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We present the first calculation of the two-loop electroweak fermionic correction to the flavour-dependent effective weak-mixing angle for bottom quarks, sin^2 theta_{eff}^{b anti-b}. For the evaluation of the missing two-loop vertex…

High Energy Physics - Phenomenology · Physics 2010-04-21 M. Awramik , M. Czakon , A. Freitas , B. A. Kniehl

In calculating electroweak radiative corrections at two-loop level, one encounters Feynman graphs with several different masses on the internal propagators and on the external legs, which lead to complicated scalar functions. We describe a…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Ghinculov , Y. -P. Yao

The complete electroweak O(alpha) corrections have been calculated for the charged-current four-fermion production processes e+e- --> nu_tau tau+ mu- anti-nu_mu, u anti-d mu- anti-nu_mu, and u anti-d s anti-c. Here, technical details of…

High Energy Physics - Phenomenology · Physics 2011-08-30 A. Denner , S. Dittmaier , M. Roth , L. H. Wieders

We present an algorithm to compute arbitrary multi-loop massive Feynman diagrams in the region where the typical energy scale \sqrt{s} is much larger than the typical mass scale M, i.e. s>>M^2, while various different energy and mass…

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

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 present new results for next-to-leading order (NLO) electroweak (EW) corrections to double polarization signals in the $WZ$ production channel at the LHC using the $e^+\nu_e \mu^+ \mu^-$ final state. It is found that the EW corrections…

High Energy Physics - Phenomenology · Physics 2022-03-04 Duc Ninh Le , Julien Baglio

Electroweak corrections associated with the instability of the top quark to the next-to-next-to-leading logarithmic (NNLL) total top pair threshold cross section in e+e- annihilation are determined. Our method is based on absorptive parts…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. H. Hoang , C. J. Reisser

First results on the radiative corrections of order O(N_f\alpha_s\alpha) are presented for the off-shell production of W or Z bosons at the LHC, where N_f is the number of fermion flavours. These corrections comprise all diagrams at…

High Energy Physics - Phenomenology · Physics 2021-02-03 Stefan Dittmaier , Timo Schmidt , Jan Schwarz

Two-loop contributions to the electromagnetic form factors are calculated in the kinematic regime close to the fermion-antifermion threshold. The results are presented in an expansion in the velocity $\beta$ of the fermions in the c.m.…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. H. Hoang

A review is given on the quantum correction $\Delta r$ in the $W$--$Z$ mass correlation at the electroweak two-loop level, as derived from the calculation of the muon lifetime in the Standard Model. Exact results for $\Delta r$ and the…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Freitas , S. Heinemeyer , W. Hollik , W. Walter , G. Weiglein

In this paper, we study the next-to-next-to-leading-order (NNLO) QCD corrections for the process $e^+e^- \to J/\psi+J/\psi$ at the $B$ factories. By including the NNLO corrections, the cross section turns negative due to the poor…

High Energy Physics - Phenomenology · Physics 2024-02-13 Xu-Dong Huang , Bin Gong , Rui-Chang Niu , Huai-Min Yu , Jian-Xiong Wang

Complete electroweak two-loop corrections to the process $gg \to H$ are presented and discussed in a Standard Model with a fourth generation of heavy fermions. The latter is studied at the LHC to put exclusion limits on a fourth generation…

High Energy Physics - Phenomenology · Physics 2015-05-30 Giampiero Passarino , Christian Sturm , Sandro Uccirati

We present next-to-leading order (NLO) calculations including QCD and electroweak (EW) corrections for $2\ell2\nu$ diboson signatures with two opposite-charge leptons and two neutrinos. Specifically, we study the processes $pp\to e^+ \mu^-…

High Energy Physics - Phenomenology · Physics 2017-12-25 S. Kallweit , J. M. Lindert , S. Pozzorini , M. Schonherr

We determine the NNLO electroweak correction to the $e^+ e^-\to b\bar{b}W^+W^- X$ production cross section near the top-pair production threshold. The calculation includes non-resonant production of the final state as well as electroweak…

High Energy Physics - Phenomenology · Physics 2018-02-28 Martin Beneke , Andreas Maier , Thomas Rauh , Pedro Ruiz-Femenia

We outline the recent results on the two-loop electroweak contributions to the electron-electron scattering cross sections and asymmetries. Although the two-loop corrections are strongly suppressed relative to the one-loop corrections, they…

High Energy Physics - Phenomenology · Physics 2014-11-18 A. Aleksejevs , S. Barkanova , V. Zykunov

Two-loop electroweak corrections to the electron, muon, and tau lepton anomalous magnetic moments have been computed recently. Effects of hadronic contributions to the photon propagator in two-loop QED corrections have also been reanalysed.…

High Energy Physics - Phenomenology · Physics 2011-04-15 Andrzej Czarnecki , Bernd Krause

Inspired by the recent observation of the Higgs boson radiative decay into $Z^0$ by {\tt ATLAS} and {\tt CMS} Collaborations, we investigate the next-to-leading-order (NLO) electroweak correction to this rare decay process in Standard Model…

High Energy Physics - Phenomenology · Physics 2024-09-23 Wen-Long Sang , Feng Feng , Yu Jia

We review the techniques necessary for the calculation of virtual electroweak and soft photonic corrections at the one-loop level. In particular we describe renormalization, calculation of one-loop integrals and evaluation of one-loop…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ansgar Denner

We present the complete analytical result for the two-loop logarithmically enhanced contributions to the high energy asymptotic behavior of the vector form factor and the four-fermion cross section in a spontaneously broken SU(2) gauge…

High Energy Physics - Phenomenology · Physics 2014-11-18 Bernd Jantzen , Johann H. Kühn , Alexander A. Penin , Vladimir A. Smirnov

In the paper we recalculate and discuss high-precision theoretical predictions for cross sections of the process $e^+e^- \to Z Z$. We assume a complete one-loop implementation and a possibility of estimating the initial state polarizations,…

High Energy Physics - Phenomenology · Physics 2024-01-25 S. Bondarenko , Ya. Dydyshka , L. Kalinovskaya , R. Sadykov , V. Yermolchyk