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arXiv · 2211.16562

Hadronic light-by-light contribution to the muon $g-2$ from holographic QCD with solved $U(1)_A$ problem

Josef Leutgeb·Jonas Mager·Anton Rebhan
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Abstract

We employ the comparatively minimal extension of hard-wall AdS/QCD due to Katz and Schwartz which takes into account the U(1)$_A$ anomaly for computing hadronic light-by-light scattering contributions of pseudoscalar and axial vector mesons to the anomalous magnetic moment of the muon $a_\mu$. By including a gluon condensate as one extra tunable parameter besides those fixed by $f_\pi$ and the pion, kaon, and rho masses, we obtain remarkably accurate fits for $\eta$ and $\eta'$ masses and their decay rates to photons, leading to $a_\mu$ contributions in complete agreement with the Standard Model result by the Muon $g-2$ Theory Initiative. Turning to the less well understood axial vector contributions, we update our previous predictions obtained in flavor-symmetric hard-wall AdS/QCD models without U(1)$_A$ breaking.

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Josef Leutgeb, Jonas Mager, Anton Rebhan. 2022-11-29. Hadronic light-by-light contribution to the muon $g-2$ from holographic QCD with solved $U(1)_A$ problem. https://doi.org/10.1103/physrevd.107.054021

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