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Related papers: Electromagnetic form factor of the pion

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We report on the contributions to the nucleon weak magnetic and electric form factors arising from isospin-breaking form factors. The relativized quark model used in the calculations includes isospin impurities in the large basis nucleon…

Nuclear Theory · Physics 2007-05-23 Simon Capstick , D. Robson

We derive an analytic result for the pion pole contribution to the light-by-light scattering correction to the anomalous magnetic moment of the muon, $a_\mu = (g_\mu-2)/2$. Using the vector meson dominance model (VMD) for the pion…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ian Blokland , Andrzej Czarnecki , Kirill Melnikov

We describe some recent results on isospin breaking corrections which are of relevance for predictions of the leading order hadronic contribution to the muon anomalous magnetic moment (amuhadLO) when using tau lepton data. When these…

High Energy Physics - Phenomenology · Physics 2015-05-18 G. Lopez Castro

The pion electromagnetic form factor at spacelike momentum transfer is calculated in relativistic impulse approximation using the Covariant Spectator Theory. The same dressed quark mass function and the equation for the pion bound-state…

High Energy Physics - Phenomenology · Physics 2014-01-09 Elmar P. Biernat , Franz Gross , M. T. Peña , Alfred Stadler

We compute the electromagnetic charged kaon form factor in the time-like region by employing a Poincar\'e covariant formalism of the Bethe-Salpeter equation to study quark-antiquark bound states in conjunction with the Schwinger-Dyson…

High Energy Physics - Phenomenology · Physics 2023-02-01 A. S. Miramontes , Adnan Bashir

The muon has been instrumental in establishing the Standard Model of particle physics and continues to play a key role in exploring the nature of New Physics. A global program is underway to enhance the discovery potential of a wide range…

High Energy Physics - Phenomenology · Physics 2026-02-16 Bertrand Echenard , Alexey A. Petrov

The pion electromagnetic form factor is investigated by using the dispersion relation with the superconvergence condition, which was proposed to synthesize the vector meson dominance model and QCD. The absorptive part is given as an…

High Energy Physics - Phenomenology · Physics 2007-05-23 Keiji Watanabe , Hirohisa Ishikawa , Masami Nakagawa

The electromagnetic form factor of the pion is calculated within the use of functional formalism. We develop integral representation for the minimal set of Standard Model Green's functions and derive the dispersion relation for the form…

High Energy Physics - Phenomenology · Physics 2022-09-30 Vladimir Sauli

The behaviour of the pion transition form factor for the process $\gamma^\star\gamma \to \pi^0$ and $\gamma^\star\gamma^\star\to \pi^0$ at space-like values of photon momenta is estimated within the nonlocal covariant quark-meson model. The…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. E. Dorokhov

A unified set of predictions for pion and kaon elastic electromagnetic and gravitational form factors is obtained using a symmetry-preserving truncation of each relevant quantum field equation. A key part of the study is a description of…

High Energy Physics - Phenomenology · Physics 2023-11-28 Yin-Zhen Xu , Minghui Ding , Khépani Raya , Craig D. Roberts , José Rodríguez-Quintero , Sebastian M. Schmidt

We investigate restrictions on the hadronic contribution to the muon $(g-2)$ factor and to the pion electromagnetic formfactor from the analytical properties of the pion formfactor and the experimental data of the pion formfactor in the…

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

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 most recent high-precision determination of the hadronic leading order contribution to the muon magnetic dipole moment within the Standard Model of particle physics has revealed a five standard deviation discrepancy with the previous…

High Energy Physics - Phenomenology · Physics 2023-10-06 Noah Bray-Ali

We complement studies of the neutral pion transition form factor pi^0 --> gamma^(*) gamma^(*) with calculations for the electromagnetic decay widths of the processes pi^0 --> e^+ e^-, pi^0 --> e^+ e^- gamma and pi^0 --> e^+ e^- e^+ e^-.…

High Energy Physics - Phenomenology · Physics 2017-08-02 Esther Weil , Gernot Eichmann , Christian S. Fischer , Richard Williams

The electromagnetic form factors of pion and nucleon are considered within the framework of the Quark-Gluon Strings Model, where the dependence of the form factors on $q^2$ is determined by the intercept of a dominant Regge trajectory and…

High Energy Physics - Phenomenology · Physics 2009-08-25 A. B. Kaidalov , L. A. Kondratyuk , D. V. Tchekin

The electron and muon magnetic moments have played, and continue to play, important roles in testing the fundamental mathematical description of physical reality called the Standard Model of particle physics (SM). The electron magnetic…

High Energy Physics - Experiment · Physics 2026-02-17 Gerald Gabrielse , Graziano Venanzoni

The anomalous magnetic moment of the muon displays a $4.2\sigma$ tension with the Standard-Model prediction, if $e^+e^-\to \text{hadrons}$ data are used for hadronic vacuum polarization. In these proceedings we review possible explanations…

High Energy Physics - Phenomenology · Physics 2022-07-06 Andreas Crivellin , Martin Hoferichter

We present detailed numerical results for the pion space-like electromagnetic form factor obtained within a recently proposed model of the pion electromagnetic current in a confining light-front QCD-inspired model. The model incorporates…

High Energy Physics - Phenomenology · Physics 2009-11-10 J. P. B. C. de Melo , T. Frederico , E. Pace , G. Salme

The pion-pole contribution to hadronic light-by-light scattering in the anomalous magnetic moment of the muon $(g-2)_\mu$ is fully determined by the doubly-virtual pion transition form factor. Although this crucial input quantity is, in…

High Energy Physics - Phenomenology · Physics 2018-10-26 Martin Hoferichter , Bai-Long Hoid , Bastian Kubis , Stefan Leupold , Sebastian P. Schneider

We present a determination of the pion charge radius from high precision data on the pion vector form factor from both timelike and spacelike regions, using a novel formalism based on analyticity and unitarity. At low energies, instead of…

High Energy Physics - Phenomenology · Physics 2017-10-04 B. Ananthanarayan , Irinel Caprini , Diganta Das