Overview
- An international team reports in Nature the most precise calculation of the hadronic term that drives the theory value, finding aμ LO‑HVP = 715.1 with a total uncertainty of 3.4 × 10⁻¹⁰.
- Using this input, the full Standard Model prediction now agrees with the muon g‑2 measurements to about 0.5 standard deviation, removing the long‑touted mismatch.
- The group combined supercomputer lattice QCD for short and mid distances with well‑vetted low‑energy measurements for long distances, cutting the uncertainty by about a factor of 1.6.
- The decade‑long effort reaches roughly 11‑decimal‑place accuracy and tightens the space for any new force or particle to show up, though it does not rule new physics out.
- The earlier “anomaly” grew from Brookhaven’s 3.7‑sigma hint and a combined 4.2‑sigma signal after Fermilab’s run, which had fueled hopes that the muon’s tiny magnetic offset revealed new physics.