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Related papers: Hadronic Contributions to R and g-2 from Initial-S…

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With the recent interest in the measured and standard model values of the muon anomalous magnetic moment, a_mu, some confusion has arisen concerning our knowledge of the hadronic contribution to a_mu. In the dispersion integral approach to…

High Energy Physics - Phenomenology · Physics 2007-05-23 William J. Marciano , B. Lee Roberts

The BaBar Collaboration has an intensive program of studying hadronic cross sections at low-energy $e^+e^-$ collisions, accessible via initial-state radiation. Our measurements allow significant improvements in the precision of the…

High Energy Physics - Experiment · Physics 2014-02-05 Denis Bernard

Using recently published, high-precision pi+pi- cross section data by the BABAR experiment from the analysis of e+e- events with high-energy photon radiation in the initial state, we reevaluate the lowest order hadronic contribution…

High Energy Physics - Phenomenology · Physics 2014-11-20 M. Davier , A. Hoecker , B. Malaescu , C. Z. Yuan , Z. Zhang

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

We review the recent progress achieved, using Resonance Chiral Theory, in the hadronic contributions to the muon anomalous magnetic moment. These include the hadronic vacuum polarization, either using $e^+e^-$ or $\tau$ decays into hadron…

High Energy Physics - Phenomenology · Physics 2026-02-10 Emilio J. Estrada , Alejandro Miranda , Pablo Roig

The discrepancy on the muon anomalous magnetic moment values obtained via a direct measurement and via a data-driven theory determination that uses the experimentally measured hadronic cross section, is among the long standing and most…

High Energy Physics - Experiment · Physics 2026-01-21 Zhiqing Zhang

We present results of calculations of the hadronic vacuum polarisation contribution to the muon anomalous magnetic moment. Specifically, we focus on controlling the infrared regime of the vacuum polarisation function. Our results are…

High Energy Physics - Lattice · Physics 2018-04-18 M. Della Morte , A. Francis , A. Gérardin , V. Gülpers , G. Herdoiza , G. von Hippel , H. Horch , B. Jäger , H. B. Meyer , A. Nyffeler , H. Wittig

A measurement of additional radiation in $e^+e^- \to \mu^+\mu^- \gamma$ and $e^+e^- \to \pi^+\pi^- \gamma$ initial-state-radiation events is presented using the full $BaBar$ data sample. For the first time results are presented at next-to-…

High Energy Physics - Experiment · Physics 2024-12-17 Bogdan Malaescu

I present a status report of the hadronic vacuum polarization effects for the muon $g-2$, to be considered as an update of [1]. The update concerns recent new inclusive $R$ measurements from KEDR in the energy range 1.84 to 3.72 GeV. For…

High Energy Physics - Phenomenology · Physics 2018-02-14 Fred Jegerlehner

This work presents a complete re-evaluation of the hadronic vacuum polarisation contributions to the anomalous magnetic moment of the muon, $a_{\mu}^{\rm had, \, VP}$ and the hadronic contributions to the effective QED coupling at the mass…

High Energy Physics - Phenomenology · Physics 2018-07-16 Alexander Keshavarzi , Daisuke Nomura , Thomas Teubner

We have performed a new evaluation of the hadronic contribution to $a_{\mu}=(g-2)/2$ of the muon with explicit correlations of systematic errors among the experimental data on $\sigma( e^+e^- \to hadrons )$. Our result for the lowest order…

High Energy Physics - Phenomenology · Physics 2014-11-17 D. H. Brown , W. A. Worstell

The hadronic vacuum-polarization contribution to the muon anomalous magnetic moment a_{mu}(hadr) and to the value of the eleectromagnetic coupling constant at q^2 = M^2_z are determined more precisely in connection with a new more exact…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. V. Geshkenbein

We have reevaluated the hadronic contribution to the anomalous magnetic moment of the muon (g-2) and to the running of the QED fine structure constant alpha(s) at s=M_Z**2. We incorporated new data from hadronic tau decays, recently…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Alemany , M. Davier , A. Hocker

We present a systematic study of the hadronic contributions to the muon anomalous magnetic moment within several infrared-improved AdS/QCD models. The models are constrained by the pion decay constant and the $\rho$-meson mass and are shown…

High Energy Physics - Phenomenology · Physics 2026-03-24 Jin-Yang Shen , Wen-Yuan Peng , Ling-Yun Dai , Zhen Fang

Recently, it was shown that insertions of hadronic vacuum polarization at O(alpha^4) generate non-negligible effects in the calculation of the anomalous magnetic moment of the muon. This result raises the question if other hadronic diagrams…

High Energy Physics - Phenomenology · Physics 2014-06-19 Gilberto Colangelo , Martin Hoferichter , Andreas Nyffeler , Massimo Passera , Peter Stoffer

This talk is about the hadronic light-by-light contribution to the muon anomalous magnetic moment, mainly our old work but including some newer results as well. It concentrates on the model calculations. Most attention is paid to…

High Energy Physics - Phenomenology · Physics 2018-06-13 Johan Bijnens

We present and test a new method to compute the hadronic vacuum polarization function in lattice simulations. This can then be used, e.g., to determine the leading hadronic contribution to the anomalous magnetic moment of the muon. The…

High Energy Physics - Lattice · Physics 2015-09-30 Gunnar Bali , Gergely Endrodi

We revisit the isospin-breaking and electromagnetic corrections to the decay $\tau^-\to\pi^-\pi^0\nu_\tau$, which allow its use as input in the two-pion contribution to the (leading order) hadronic vacuum polarization part of the muon…

High Energy Physics - Phenomenology · Physics 2021-01-04 J. A. Miranda , P. Roig

We evaluate the leading-order hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon with two light flavors in minimal hard-wall and soft-wall holographic QCD models, as well as in simple generalizations…

High Energy Physics - Phenomenology · Physics 2022-06-08 Josef Leutgeb , Anton Rebhan , Michael Stadlbauer

I present a new data driven update of the hadronic vacuum polarization effects for the muon and the electron $g-2$. For the leading order contributions I find $a_\mu^{\mathrm{had}(1)}=(686.99\pm 4.21)[687.19\pm 3.48]\times 10^{-10}$ based…

High Energy Physics - Phenomenology · Physics 2016-06-22 Fred Jegerlehner