New Results from the Muon g - 2 Experiment

The Muon g - 2 collaboration has measured the anomalous magnetic g value, a = (g - 2)/2, of the positive muon with an unprecedented uncertainty of 0.7 parts per million. The result aμ+(_expt^{) = 11659204(7)(5) × 10-10, based on data collected in the year 2000 at Brookhaven National Laboratory, is in good agreement with the preceeding data on aμ+} and aμ-. The measurement tests standard model theory, which at the level of the current experimental uncertainty involves quantum electrodynamics, quantum chromodynamics, and electroweak interaction in a significant way.