Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm

Abstract

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g -2 Experiment for the positive muon magnetic anomaly a g -2=2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency a between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency 0