On May 31, Fermi National Accelerator Laboratory near Chicago kicked off its Muon g-2 experiment. The three-year experiment looks to explore the interactions of muons—short-lived, unstable subatomic particles similar to electrons—under a strong magnetic field.The 50-foot wide electromagnet at Fermilab. Image credit: Fermi National Accelerator Laboratory

Muon g-2 (pronounced “g minus two”) aims to test predictions laid out by the Standard Model of particle physics by studying the precession rate of muons subjected to a magnetic field. If researchers find anomalies or inconsistencies in muon behavior, it could indicate that the Standard Model is either incomplete or in need of revision.

The experiment is a continuation of an earlier study conducted at Brookhaven National Laboratory in New York in the late 1990s and early 2000s, and also uses much of the same equipment despite the distance between labs. In 2013 Brookhaven’s 50-foot wide electromagnet was transported from New York to Chicago, first on a barge and then a specially designed truck. Fermilab staff have spent the past four years preparing for the Muon g-2 experiment by setting up detectors, building a control room and adjusting the magnetic field’s uniformity.

“It’s an exciting time for the whole team, and for physics,” said David Hertzog, co-spokesperson for the Muon g-2 collaboration. “The magnet has been working, and working fantastically well. It won’t be long until we have our first results and a better view through the window that the Brookhaven experiment opened for us.”