Detailed Report on the Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm

Understand

We present details on a new measurement of the muon magnetic anomaly, $a_\mu = (g_\mu -2)/2$.

• The result is based on positive muon data taken at Fermilab's Muon Campus during the 2019 and 2020 accelerator runs.
• The measurement uses $3.1$ GeV$/c$ polarized muons stored in a $7.1$-m-radius storage ring with a $1.45$ T uniform magnetic field.
• The value of $ a_{\mu}$ is determined from the measured difference between the muon spin precession frequency and its cyclotron frequency.