The experimental measurement of the muon's magnetic properties has diverged from Standard Model theoretical predictions for over 10 years (as of 2021).
Notes on verification
Well-documented by Brookhaven E821 (2004) and Fermilab Muon g-2 (2021) experiments; discrepancy with Standard Model predictions persisted for well over a decade, confirmed by multiple independent physics institutions and peer-reviewed/primary sources.
Sources
- Physique des particules : les muons nous mèneront-ils vers une nouvelle physique ? | CNRS (cnrs.fr)
- https://muon-g-2.fnal.gov/result2021.pdf (muon-g-2.fnal.gov)
- https://www.symmetrymagazine.org/article/april-2021/fermilab-muon-g-2-results (symmetrymagazine.org)
- https://www.bnl.gov/newsroom/news.php?a=13208 (bnl.gov)