  The Muon (g-2) Experiment (E821) at Brookhaven National Laboratory (BNL) has
measured the anomalous magnetic moment of the positive muon to an unprecedented
precision of 1.3 parts per million. The result, a_{\mu^+} = (g-2)/2 = 11 659
202(14)(6) X 10^{-10}, is based on data recorded in 1999 and is in good
agreement with previous measurements. Upcoming analysis of data recorded in
2000 and 2001 will substantially reduce the uncertainty on this measurement.
Comparison of the new world average experimental value with the most
comprehensive Standard Model calculation, a_\mu(SM) = 11 659 159.6(6.7) X
10^{-10}, yields a difference of a_\mu(exp)-a_\mu(SM) = 43(16) X 10^{-10}.

High Energy Physics - Experiment