# Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm

Article · D. P. Aguillard, T. Albahri, D. H. Allspach, A. V. Anisenkov, Karie E. Badgley, S. Baeßler, I. Bailey, L. Bailey, V. A. Baranov, E. Barlas-Yucel, Tucker Barrett, E. Barzi, F. Bedeschi, Martin Berz, Meghna Bhattacharya, H. P. Binney, Paul C Bloom, J. Bono, E. Bottalico, T. J. V. Bowcock, S. Braun, M. Bressler, G. Cantatore, R. M. Carey, B. C. K. Casey and 75 more

- Archive id: doi:10.1103/physrevlett.131.161802
- Published: 2023-10-17
- Venue: Physical Review Letters
- DOI: https://doi.org/10.1103/physrevlett.131.161802
- PMID: 37925710
- Citations: 368
- Source URL: https://doi.org/10.1103/physrevlett.131.161802
- PDF: http://link.aps.org/pdf/10.1103/PhysRevLett.131.161802
- Provenance: openalex

## Abstract

We present a new measurement of the positive muon magnetic anomaly, a\_{μ}≡(g\_{μ}-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, ω\[over ˜\]\_{p}^{'}, and of the anomalous precession frequency corrected for beam dynamics effects, ω\_{a}. From the ratio ω\_{a}/ω\[over ˜\]\_{p}^{'}, together with precisely determined external parameters, we determine a\_{μ}=116 592 057(25)×10^{-11} (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain a\_{μ}(FNAL)=116 592 055(24)×10^{-11} (0.20 ppm). The new experimental world average is a\_{μ}(exp)=116 592 059(22)×10^{-11} (0.19 ppm), which represents a factor of 2 improvement in precision.

_Abstract reproduced under CC-BY (publisher license, via OpenAlex)._

Topics: [Particle Physics & Beyond the Standard Model](https://space-kitty.com/topics/particle-physics-bsm)

Cited in dossiers:
- [Particle Physics & Beyond the Standard Model: State of the Field (October 2026)](https://space-kitty.com/dossiers/particle-physics-bsm)

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