The particle célèbre is the muon, which is akin to an electron but far heavier, and is an integral element of the cosmos. Dr. Polly and his colleagues — an international team of 200 physicists from seven countries — found that muons did not behave as predicted when shot through an intense magneti...

Meanwhile, in 2020, a group of 170 experts known as the Muon g-2 Theory Initiative published a new consensus value of the theoretical value of the muon’s magnetic moment , based...

But they are 207 times as massive as their better-known cousins. They are also unstable, decaying radioactively into electrons and super-lightweight particles called neutrinos in 2.2 millionths of a second.

It might also lead in time to explanations for the kinds of cosmic mysteries that have long preoccupied our lonely species. What exactly is dark matter , the unseen stuff that astronomers say makes up one...

The measurements have about one chance in 40,000 of being a fluke, the scientists reported, well short of the gold standard needed to claim an official discovery by physics standards. Promising signals disappear all the time in science, but more data are on the way. Wednesday’s results represent ...

Muons are an unlikely particle to hold center stage in physics. Sometimes called “fat electrons,” they resemble the familiar elementary particles that power our batteries, lights and computers and whiz around the nuclei of atoms; they have a negative electrical charge, and they have a property ca...

This entourage influences the behavior of existing particles, including a property of the muon called its magnetic moment, represented in equations by a factor called g. According to a formula derived in 1928 by Paul Dirac, the English theoretical physicist and a founder of quantum theory, the g ...