Long-awaited muon experiment nears moment of truth

A result that has been 20 years in the making could reveal the existence of new particles and upend fundamental physics. Physicists have high hopes that the magnetism of muons, measured in the Muon g – 2 experiment and scheduled to be released on 7 April, will uphold sensational findings first announced in 2001. The project’s earlier results hinted that the muon’s magnetic moment — a measure of the magnetic field it generates — is slightly larger than theory had predicted. If that finding is ultimately confirmed, it could help to reveal what kinds of ephemeral, unknown ‘virtual particles’ swirl in the vacuum.