A new precision measurement of the anomalous magnetic moment of the positive muon
Alexei Vitalyevich Trofimov · CERN Document Server (European Organization for Nuclear Research) · 2002
This dissertation presents the analysis and results of the measurement of the anomalous magnetic moment of the positive muon (a μ). The experiment was conducted at the Alternating Gradient Synchrotron at Brookhaven National Laboratory (BNL). Polarized muons were stored in a uniform magnetic field, and aμ was determined by measuring the free proton nuclear magnetic resonance frequency (ω p) in that magnetic field, and the difference between the muon spin precession and cyclotron frequencies (ωa). The experiment began taking data in 1997. A detailed analysis of the frequency ωa, using a multi- parameter fit is presented, based on the data set from the third experimental run (1999). The new experimental result has a precision of 1.35 parts per million (ppm): aexp m (BNL, 1999) = 11 659 202(16) × 10 −10 . It agrees well with previous measurements. The weighted mean of all measurements to date shows a difference of 2.6 standard deviations from the Standard Model (SM) prediction ( aSM m ): aexp m - aSM m = 43±16 × 10-10. This difference may suggest the presence of physics beyond the Standard Model.