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Related papers: Two-loop radiative corrections to $e^+ e^-\rightar…

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A new evaluation of the hadronic vacuum polarization contribution to the muon magnetic moment is presented. We take into account the reanalysis of the low-energy e+e- annihilation cross section into hadrons by the CMD-2 Collaboration. The…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Davier , S. Eidelman , A. Hocker , Z. Zhang

Vacuum polarization is a part of the initial-state radiative correction for the cross-section of $e^+e^-$ annihilation processes. In the energy region in the vicinity of narrow resonances $J/\psi$ and $\psi(3686)$, the vacuum polarization…

High Energy Physics - Phenomenology · Physics 2018-12-18 Hong-Dou Jin , Li-Peng Zhou , Bing-Xin Zhang , Hai-Ming Hu

Quantum loops induce an anomaly, a_mu, in the magnetic moment of the muon that can be accurately measured. Its Standard Model prediction is limited in precision by contributions from hadronic vacuum polarisation of the photon. The dominant…

High Energy Physics - Phenomenology · Physics 2011-09-20 Andreas Hoecker

We study the impact of the two-loop electroweak corrections on the production of a Higgs boson via gluon-fusion in proton-proton collisions at LHC energies. We discuss the prescritpion to include the corrections to the hard scattering…

High Energy Physics - Phenomenology · Physics 2007-05-23 U. Aglietti , R. Bonciani , G. Degrassi , A. Vicini

The hadronic light-by-light contribution to a_{mu}, the anomalous magnetic moment of the muon, is discussed from the point of view of an effective low-energy theory. As an application, the coefficient of the leading logarithm arising from…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Knecht , A. Nyffeler , M. Perrottet , E. de Rafael

We describe the calculation of the two--loop massive operator matrix elements for massive external fermions. These matrix elements are needed for the calculation of the $O(\alpha^2)$ initial state radiative corrections to $e^+e^-$…

High Energy Physics - Phenomenology · Physics 2009-04-14 J. Blümlein , A. De Freitas , W. van Neerven

We apply the modern multiloop methods to the calculation of the total cross sections of electron-positron annihilation to 2 and 3 photons exactly in $s/m^2$ with the accuracy $O(\alpha^3)$. Examining the asymptotics of our results, we find…

High Energy Physics - Phenomenology · Physics 2020-10-28 Roman N. Lee

We give an update of our calculation of the light-quark, connected, hadronic vacuum polarization contribution to the muon anomalous magnetic moment, or muon $g-2$. The update includes preliminary results on a $2 + 1 + 1$ highly-improved…

High Energy Physics - Lattice · Physics 2026-03-02 Vaishakhi Moningi , Christopher Aubin , Thomas Blum , Maarten Golterman , Luchang Jin , Santiago Peris

We give a short description of the present situation of lattice QCD simulations. We then focus on the computation of the anomalous magnetic moment of the muon using lattice techniques. We demonstrate that by employing improved observables…

High Energy Physics - Lattice · Physics 2015-06-03 X. Feng , K. Jansen , M. Petschlies , D. Renner

The two-loop electroweak bosonic correction to the muon lifetime is computed using methods of asymptotic expansion. Combined with previous calculations this completes the full two-loop correction to $\Delta r$ in the Standard Model.

High Energy Physics - Phenomenology · Physics 2011-07-19 A. Onishchenko , O. Veretin

We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium generated by the diagrams with electron and muon vacuum polarizations. We calculate single-logarithmic and nonlogarithmic contributions of order…

High Energy Physics - Phenomenology · Physics 2010-01-26 Michael I. Eides , Valery A. Shelyuto

We present the NNLO QCD virtual corrections for qurak-antiquark -> gluon photon, quark-antiquark -> photon photon and the NNLO QED virtual corrections for electron positron -> photon photon and all processes related by crossing symmetry. We…

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

A hadronic vacuum polarization correction to the photon propagator is found by using the Dubnicka-Meshcheryakov parameterization of the pion electromagnetic form factor and new experimental data on the $e^+e^-$ hadrons annihilation cross…

High Energy Physics - Phenomenology · Physics 2021-12-30 V. P. Gerdt , A. Karimkhodzhaev , R. N. Faustov

We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the $Z$-boson mass. We include newest $e^+e^- \to$ hadrons cross-section data together…

High Energy Physics - Phenomenology · Physics 2020-03-19 M. Davier , A. Hoecker , B. Malaescu , Z. Zhang

We compute two-loop electroweak corrections to double Higgs boson production in gluon fusion mediated by light quarks in a fully analytical way. We determine a basis of master integrals satisfying canonical differential equations in…

High Energy Physics - Phenomenology · Physics 2025-06-03 Marco Bonetti , Philipp Rendler , William J. Torres Bobadilla

Recently, the Budapest-Marseille-Wuppertal collaboration achieved sub-percent precision in the evaluation of the lowest-order hadronic vacuum polarization contribution to the muon $g_\mu-2$ (arXiv:hep-lat/2002.12347v3). At this level of…

The current status of electroweak radiative corrections to the muon anomalous magnetic moment is discussed. Asymptotic expansions for some important electroweak two loop top quark triangle diagrams are illustrated and extended to higher…

High Energy Physics - Phenomenology · Physics 2017-12-22 Andrzej Czarnecki , William J. Marciano

We consider electroweak (EW) virtual corrections to $2\to 2$ fermion scattering processes mediated by a vector boson $V$ ($V=W^\pm,Z$) in the pole approximation. As is well known, the computation can be organised into factorisable and…

High Energy Physics - Phenomenology · Physics 2026-05-12 Fazila Ahmadova , Luca Buonocore , Massimiliano Grazzini , Chiara Savoini

Based on analyticity, unitarity, and Lorentz invariance the contribution from hadronic vacuum polarization to the anomalous magnetic moment of the muon is directly related to the cross section of e^+e^- --> hadrons. We review the main…

High Energy Physics - Phenomenology · Physics 2015-06-17 Martin Hoferichter , Gilberto Colangelo , Massimiliano Procura , Peter Stoffer

I provide updates for the theoretical predictions of the muon and electron anomalous magnetic moments, for the shift in the fine structure constant $\alpha(M_Z)$ and for the weak mixing parameter $\sin^2 \Theta_W(M_Z)$. Phenomenological…

High Energy Physics - Phenomenology · Physics 2017-11-17 Fred Jegerlehner