Center for Experimental Nuclear Physics and Astrophysics

On June 3, scientists working on the Muon g-2 experiment (pronounced "mew-on gee-minus-two") released the third and final measurement of the muon magnetic anomaly. This result agrees with the published results from 2021 and 2023 but with a much better precision of 127 parts per billion, surpassing the original experimental design goal of 140 parts per billion.

A particle physics experiment decades in the making — the Muon g-2 experiment — looks increasingly like it might set up a showdown over whether there are fundamental particles or forces in the universe that are unaccounted for in the current Standard Model. On Aug. 10, the international team of scientists behind Muon g-2 — pronounced “g minus 2” — released the world’s most precise measurement yet of the anomalous magnetic moment of the muon. Calculating the muon’s magnetic moment at a high precision will indicate whether it is interacting solely with the particles and forces known today, or if unknown particles or forces are out there.

David Hertzog, professor of physics, explains the results of new research on muons, a type of particle.

When considering what makes up the universe, it’s surprising that scientists could focus on just one yes/no question. But that’s exactly what a group of researchers supported by the Heising-Simons Foundation is doing.