Overview

• The Muon g−2 experiment at Fermilab has yielded a measurement of the muon's anomalous magnetic moment with an uncertainty of just 127 parts per billion using more than twice the data of its 2023 results.
• Researchers have replaced experimental data-driven hadronic vacuum polarization inputs with ab initio lattice quantum chromodynamics calculations in the theoretical prediction.
• The revised theoretical value now matches the experimental measurement, closing a discrepancy that persisted for nearly 25 years.
• The agreement between theory and experiment affirms the Standard Model's description of muon magnetism and undermines numerous proposed theories for new physics.
• Unresolved differences in the CMD-3 experiment's results continue to demand scrutiny, and upcoming measurements at the Japan Proton Accelerator Research Complex are planned to probe these anomalies further.