Dispersion relation for hadronic light-by-light scattering: pion pole

By M. Hoferichter, Bai-Long Hoid, B. Kubis, S. Leupold, S. Schneider. Journal of High Energy Physics, 2018

297 citations recorded by the source corpus.

The pion-pole contribution to hadronic light-by-light scattering in the anomalous magnetic moment of the muon (g − 2)μ is fully determined by the doubly-virtual pion transition form factor. Although this crucial input quantity is, in principle, directly accessible in experiment, a complete measurement covering all kinematic regions relevant for (g −2)μ is not realistic in the foreseeable future. Here, we report in detail on a reconstruction from available data, both space- and time-like, using a dispersive representation that accounts for all the low-lying singularities, reproduces the correct high- and low-energy limits, and proves convenient for the evaluation of the (g − 2)μ loop integral. We concentrate on the systematics of the fit to e+e− → 3π data, which are key in constraining the isoscalar dependence, as well as the matching to the asymptotic limits. In particular, we provide a detailed account of the pion transition form factor at low energies in the time- and space-like region, including the error estimates underlying our final result for the pion-pole contribution, aμπ0−pole=62.6−2.5+3.0×10−11\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {a}_{\mu}^{\uppi^0-\mathrm{pole}}={62.6}_{-2.5}^{+3.0}\times {10}^{-11} $$\end{document}, and demonstrate how forthcoming singly-virtual measurements will further reduce its uncertainty.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/459971a04438d6b49df371dbb6552376300bbdda

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In Nuclear and High Energy Physics

1. B. Kubis
2. Bai-Long Hoid
3. M. Hoferichter
4. T. Teubner
5. A. Keshavarzi
6. Timothy E. Chupp

Citations in the corpus

• Measurement of the anomalous precession frequency of the muon in the Fermilab Muon g−2 Experiment (2021, background): “[27] M.”
• Three-pion contribution to hadronic vacuum polarization (2019, methodology): “We take essentially the same parameterization as in [17, 18]”