Muon surplus leaves physicists searching for answers

Excess of subatomic particles produced by cosmic rays might signal new state of matter

Pierre Auger Observatory

MANY MUONS Scientists at the Pierre Auger Observatory use telescopes (pictured above) and water tanks to detect showers of particles created by high-energy protons or atomic nuclei from space. Scientists have found more muons, or larger versions of electrons, than expected in such showers.

Pierre Auger Observatory/flickr (CC BY-SA 2.0)

Muons, electrons’ heftier cousins, rain down through the Earth’s atmosphere in numbers higher than physicists expect.