On June 3, 2025, the Muon g-2 experiment at Fermilab announced its final results, marking a significant advancement in particle physics. The experiment precisely measured the magnetic moment of the muon, an unstable elementary particle, with unprecedented accuracy.
The Muon's Magnetic Moment
Muons, similar to electrons but heavier, interact with magnetic fields, and their magnetic moment is highly sensitive to the fundamental forces described by the Standard Model. For years, a discrepancy existed between experimental data and theoretical calculations, challenging physicists' understanding.
A Triumph for the Standard Model
The latest findings, with a precision of 127 parts per billion, align with the Standard Model's predictions. This agreement validates the model, which describes the fundamental forces and particles in the universe. This breakthrough strengthens confidence in the Standard Model and opens new avenues for exploring physics beyond it.