Something's afoot ...

New physics might be in play as the decay of the "beloved" muon, a very heavy cousin of the electron, differs slightly from Standard Model findings, a result, if proven to be true, may point the way to finally finding out what dark matter is actually made of.

The Moon's cosmic ray shadow, as seen in secondary muons generated by cosmic rays in the atmosphere, and detected 700 meters below ground, at the Soudan 2 detector

Scientists from the U.S. Department of Energy's (DOE) Argonne National Laboratory and Fermi National Accelerator Laboratory, along with collaborators from 46 other institutions and seven countries, are conducting an experiment to put our current understanding of the universe to the test. The first result points to the existence of undiscovered particles or forces. This new physics could help explain long-standing scientific mysteries, and the new insight adds to a storehouse of information that scientists can tap into when modeling our universe and developing new technologies.

The Standard Model very precisely predicts the muon's g-factor—a value that tells scientists how this particle behaves in a magnetic field. This g-factor is known to be close to the value two, and the experiments measure their deviation from two, hence the name Muon g-2.

The experiment at Brookhaven indicated that g-2 differed from the theoretical prediction by a few parts per million. This miniscule difference hinted at the existence of unknown interactions between the muon and the magnetic field—interactions that could involve new particles or forces.

How awesome is that?

The experiment ...

The muon g-2 magnetic storage ring, seen here at Brookhaven National Laboratory in New York before its 2013 relocation to Fermi National Accelerator Laboratory in Illinois. Credit: Alamy