ISSN - 15507998, Physical Review D - Particles, Fields, Gravitation and Cosmology, 2000, vol. 62, p. 1-4
Improved measurement of the positive muon anomalous magnetic moment
A new measurement of the positive muon's anomalous magnetic moment has been made at the Brookhaven Alternating Gradient Synchrotron using the direct injection of polarized muons into the superferric storage ring. The angular frequency difference ωa between the angular spin precession frequency ωs and the angular orbital frequency ωc is measured as well as the free proton NMR frequency ωp. These determine R =ωa/ωp=3.707 201(19)×10-3. With μμ/μp=3.183 345 39(10) this gives aμ+=11 659 191(59)×10-10 (±5 ppm), in good agreement with the previous CERN and BNL measurements for μ+ and μ-, and with the standard model prediction. ©2000 The American Physical Society.