Measurement of the anomalous precession frequency of the muon in the Fermilab Muon g-2 experiment

TL;DR

The Fermilab Muon g-2 experiment precisely measured the muon's anomalous precession frequency, providing a key value for testing the Standard Model and revealing potential new physics beyond current theories.

Contribution

This work presents the first high-precision measurement of the muon precession frequency at Fermilab, including advanced data analysis techniques and systematic uncertainty assessments.

Findings

Measured muon anomalous precession frequency with 434 ppb statistical uncertainty

Determined muon magnetic anomaly as 116592040(54) x 10^{-11}

Achieved a total uncertainty of 0.46 ppm in the measurement

Abstract

The Muon g-2 Experiment at Fermi National Accelerator Laboratory (FNAL) has measured the muon anomalous precession frequency $\omega_a$ to an uncertainty of 434 parts per billion (ppb), statistical, and 56 ppb, systematic, with data collected in four storage ring configurations during its first physics run in 2018. When combined with a precision measurement of the magnetic field of the experiment's muon storage ring, the precession frequency measurement determines a muon magnetic anomaly of $a_{\mu}({\rm FNAL}) = 116\,592\,040(54) \times 10^{-11}$ (0.46 ppm). This article describes the multiple techniques employed in the reconstruction, analysis and fitting of the data to measure the precession frequency. It also presents the averaging of the results from the eleven separate determinations of \omega_a, and the systematic uncertainties on the result.