The anomalous magnetic moment of the muon: status and perspectives

TL;DR

This paper reviews the current status of the muon's anomalous magnetic moment as a precision test for new physics, highlighting recent experimental results, theoretical challenges, and future prospects for improved measurements and predictions.

Contribution

It provides a comprehensive overview of recent experimental and theoretical developments in muon g-2 research, emphasizing the need for improved Standard Model predictions and future experimental strategies.

Findings

FNAL measurement sets new precision standards

SM prediction requires a fourfold improvement

Discussion of future experimental and theoretical advancements

Abstract

We review the status of the anomalous magnetic moment of the muon as a precision probe of physics beyond the Standard Model (SM) after the release of the final results from the Fermi National Accelerator Laboratory (FNAL) Muon $g-2$ experiment and the second White Paper of the Muon $g-2$ Theory Initiative. While the SM prediction requires further improvements by a factor of four to fully leverage the sensitivity achieved in experiment, the FNAL measurement will set the standard for many years to come, and we discuss a variety of features of the experimental campaign that made this achievement possible. In going forward, we discuss current efforts to improve the SM prediction, and imagine how an experiment would have to be devised to surpass 124 ppb in precision.