Muon g — 2 experiment at Brookhaven National Laboratory

A precise measurement of the anomalous g value, a(mu)(+) = (g - 2)/2, for the positive muon has been made at the Brookhaven Alternating Gradient Synchrotron. The result a(mu)(+) = 11 659 202(14)(6) x 10(-10) (1.3 ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The current theoretical value from the standard model is a(mu) (SM)= 11 659 159.6(6.7) x 10(-10) (0.57 ppm) and a(mu)(exp)-a(mu)(SM) = 42(16) x 10(-10) in which a(mu)(exp) is the world average experimental value.