News Particle Physics

There’s a new measurement of muon magnetism. What it means isn’t clear

The measurement is the most precise yet, but theoretical predictions are muddled

A photo of the doughnut-shaped magnet that was used with the Muon g-2 experiment.

Physicists with the Muon g−2 experiment studied how muons wobbled as they circulated within a doughnut-shaped magnet (pictured) and made the most precise measurement of a magnetic property of the particle.

Ryan Postel/Fermilab

By Emily Conover

Muons might not behave as expected. But scientists can’t agree on what to expect.

By taking stock of how the subatomic particles wobble in a magnetic field, physicists have pinned down a property of the muon’s internal magnet to greater precision than ever before, researchers from the Muon g−2 experiment reported August 10 in a seminar hosted by Fermilab in Batavia, Ill.