A discrepancy in the measurement of a type of particle decay had raised hopes of new physics
the mass of a particle called the W boson to be greater than expected, announced in April. But a separate anomaly, also involving muons, could be going away. The muon’s magnetic moment had seemed to be stronger than predicted by the standard model, but the latest theoretical calculations suggest that it is not, after all. Instead, the discrepancy could have originated in miscalculations of the standard model’s predictions.
This article is reproduced with permission and was first published on December 20 2022.
ABOUT THE AUTHOR(S)
Davide Castelvecchi is a staff reporter at Nature who has been obsessed with quantum spin for essentially his entire life. Follow him on Twitter @dcastelvecchi
