The Next-generation Muon (g−2) Experiment

The muon (g − 2) experiment at the Brookhaven AGS achieved a relative precision on the muon anomalous magnetic moment, a μ , of ±0.54 ppm. The anomaly is sensitive to a wide range of physics beyond the standard model such as supersymmetry, and thus can help constrain the interpretation of any " new physics " found at the Large Hadron Collider. It is desirable to improve the precision of the experiment and of the theoretical (standard-model) value. A new experiment to improve the precision of a μ to ±0.14 ppm is being discussed for Fermilab or J-PARC. The existing precision muon storage ring would be moved to one of these facilities. In parallel, a significant worldwide effort to improve the uncertainty on the standard model value is underway, and over the next several years could produce a significant improvement in the theory uncertainty. c Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.