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Standard Model Prediction for Muon Anomalous Magnetic Moment Revealed

Strategic Insights

— 1 min read

Researchers at Johannes Gutenberg University of Mainz, in collaboration with numerous international partners, have presented an update to the Standard Model (SM) prediction for the muon anomalous magnetic moment, aμ. This update incorporates a reevaluation of the pure QED and electroweak contributions, while the hadronic contributions continue to be the primary source of uncertainty. The research has been supported by a wide array of international organizations, including the High Energy Accelerator Research Organization, the Flavor Physics International research center in Nagoya University, and the U.S.-Japan Science and Technology Cooperation Program in High Energy Physics.

Key Takeaways:

  • The new SM prediction for aμ is 116592033(62) x 10^(-11) (530 ppb), with a major upward shift compared to the previous prediction.
  • The uncertainty of the SM prediction is mainly due to the hadronic contributions, which continue to be a significant source of uncertainty.
  • The research emphasizes the importance of resolving the tensions among data-driven dispersive evaluations of the leading-order hadronic vacuum polarization (LO HVP) contribution.
  • The authors note that significant progress has been made in the hadronic light-by-light scattering contribution using a combination of data-driven dispersive approaches and lattice-QCD calculations.
  • The new measurement of the e+e- π+π- cross-section by CMD-3 has increased the tensions among data-driven dispersive evaluations of the LO HVP contribution.
  • The attainable precision of lattice-QCD calculations has increased substantially, allowing for a consolidated lattice-QCD average of the LO HVP contribution with a precision of about 0.9%.
  • The research has been peer-reviewed and published in the Physics Reports-review Section of Physics Letters.

Statistics:

  • The new SM prediction for aμ is 116592033(62) x 10^(-11) (530 ppb).
  • The previous SM prediction for aμ was not explicitly stated in the source material.
  • The uncertainty of the SM prediction is approximately 530 ppb.
  • The hadronic contributions continue to be the primary source of uncertainty, accounting for a large portion of the total uncertainty.
  • The research has been supported by over 40 international organizations, including research centers, universities, and funding agencies.

Sources:

  • NewsRx. Data on Information Technology Described by Researchers at Johannes Gutenberg University of Mainz (The Anomalous Magnetic Moment of the Muon In the Standard Model: an Update). Information Technology Newsweekly. November 4, 2025; p 95.
  • The Anomalous Magnetic Moment of the Muon In the Standard Model: an Update. Physics Reports-review Section of Physics Letters, 2025;1143:1-158.

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