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I present recent calculations of the hadronic contributions to muon anomalous magnetic moment in holographic QCD, based on gauge/gravity duality. The holographic estimates are compared well with the analysis based on recently revised BaBar…

High Energy Physics - Phenomenology · Physics 2017-08-23 Deog Ki Hong

The evaluation of the hadronic contribution to the muon magnetic anomaly $a_\mu$ is revisited, taking advantage of new experimental data on $e^+e^-$ annihilation into hadrons: SND and CMD-2 for the $\pi^+\pi^-$ channel, and \babar for…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michel Davier

We have measured the cross section $\sigma(e^+e^-\to \pi^+\pi^- \gamma)$ at an energy $W=m_\phi=1.02$ GeV with the KLOE detector at the electron-positron collider DA$\Phi$NE. From the dependence of the cross section on the invariant mass of…

High Energy Physics - Experiment · Physics 2008-11-26 The KLOE Collaboration , A. Aloisio

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 (among others)…

High Energy Physics - Phenomenology · Physics 2019-05-10 Michel Davier , Andreas Hoecker , Bogdan Malaescu , Zhiqing Zhang

We compute the charged pion loop contribution to the muon anomalous magnetic moment $a_\mu$, taking into account the effect of the charged pion polarizability, $(\alpha_1-\beta_1)_{\pi^+}$. We evaluate this contribution using two different…

High Energy Physics - Phenomenology · Physics 2015-12-30 Kevin T. Engel , Michael J. Ramsey-Musolf

The leading-order hadronic contribution to the muon magnetic moment anomaly $a_\mu\equiv (g_\mu-2)/2$, calculated using a dispersion integral of $e^+e^-$ annihilation data and $\tau$ data, is briefly reviewed. This contribution has the…

High Energy Physics - Phenomenology · Physics 2013-12-31 Zhiqing Zhang

A comprehensive as of November 2003 and evaluated data compilation on sigma_tot(e+ e- --> hadrons) was used to estimate the lowest order hadronic contribution to the muon anomalous magnetic moment. The preliminary result is a_mu(had, LO) =…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. V. Ezhela , S. B. Lugovsky , O. V. Zenin

We present a calculation of the $C$-odd radiative corrections to $e^+e^-\to \pi^+\pi^-$ in a dispersive formalism, concentrating on the leading pion-pole contribution in the virtual box diagrams. In particular, we show how the effect of a…

High Energy Physics - Phenomenology · Physics 2025-02-27 Gilberto Colangelo , Martin Hoferichter , Joachim Monnard , Jacobo Ruiz de Elvira

The lowest order hadronic contribution to the $g-2$ factor of the muon is analyzed in the framework of the operator product expansion at short distances, and a QCD finite energy sum rule designed to quench the role of the $e^+ e^-$ data.…

High Energy Physics - Phenomenology · Physics 2013-08-09 S. Bodenstein , C. A. Dominguez , K. Schilcher , H. Spiesberger

This article reviews and updates the Standard Model prediction of the muon g-2. QED, electroweak and hadronic contributions are presented, and open questions discussed. The theoretical prediction deviates from the present experimental value…

High Energy Physics - Phenomenology · Physics 2009-07-09 M. Passera

The recently evaluated two-pion contribution to the muon g-2 and the phase of the pion electromagnetic form factor in the elastic region, known from \pi\pi scattering by Fermi-Watson theorem, are exploited by analytic techniques for finding…

High Energy Physics - Phenomenology · Physics 2011-05-13 B. Ananthanarayan , Irinel Caprini , I. Sentitemsu Imsong

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 study the constraints arising on the expansion parameters c and d of the Pion electromagnetic form factor from the inclusion of pure space-like data and the phase of time-like data along with one space-like datum, using as input the…

High Energy Physics - Phenomenology · Physics 2009-07-22 Gauhar Abbas , B. Ananthanarayan , S. Ramanan

We summarize recent developments in the Standard-Model evaluation of the anomalous magnetic moment of the muon $a_\mu$, both in the hadronic-light-by-light and hadronic-vacuum-polarization contributions. The current situation for the latter…

High Energy Physics - Phenomenology · Physics 2023-08-09 Gilberto Colangelo , Martin Hoferichter , Peter Stoffer

We argue that high-quality data on the reaction $e^+e^-\to \pi^+\pi^-\eta$ will allow one to determine the doubly-virtual form factor $\eta\to \gamma^*\gamma^*$ in a model-independent way with controlled accuracy. This is an important step…

High Energy Physics - Phenomenology · Physics 2021-11-17 S. Holz , J. Plenter , C. W. Xiao , T. Dato , C. Hanhart , B. Kubis , U. -G. Meißner , A. Wirzba

The role of the reaction e+e- --> e+ e-pi+pi- in the pion form factor measurements via radiative return method without photon tagging is studied in detail. The analysis is based on the developed Monte Carlo program EKHARA, which ingredients…

High Energy Physics - Phenomenology · Physics 2009-11-11 Henryk Czyz , Elzbieta Nowak-Kubat

Analytic calculation are presented of the contribution to the anomalous magnetic moment of a muon from the channels of annihilation of an electron-positron pair to a pair of charged pi-mesons with radiative correction connected with the…

High Energy Physics - Phenomenology · Physics 2013-08-14 A. I. Ahmadov , E. A. Kuraev , M. K. Volkov , O. O. Voskresenskaya , E. V. Zemlyanaya

A model is developed for electromagnetic form factor of the pion. One-loop corrections are included in the linear sigma-model. The rho-meson contribution is added in an extended VMD model. The form factor, calculated without fitting…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. K. Dubinsky , A. Yu. Korchin , N. P. Merenkov

Using the field-theory-inspired expression for the pion electromagnetic form factor F_\pi, a good description of the data in the range -10<s<1 GeV^2 is obtained upon taking into account the pseudoscalar-pseudoscalar (PP) loops. When the…

High Energy Physics - Phenomenology · Physics 2013-11-15 N. N. Achasov , A. A. Kozhevnikov

The cross section for the process $e^+e^-\to\pi^+\pi^-$ is measured in the c.m. energy range 1.04-1.38 GeV from 995 000 selected collinear events including 860000 $e^+e^-$ events, 82000 $\mu^+\mu^-$ events, and 33000 $\pi^+\pi^-$ events.…

High Energy Physics - Experiment · Physics 2012-08-27 2 Collaboration , V. M. Aulchenko