Natalie Wolchover (

Muon Ring

Preliminary results of a study of elementary particles at Fermilab and elsewhere show that the behavior of particles called muons deviates from standard physical theories, indicating that previously unknown forces are acting.

There is growing evidence that a tiny subatomic particle does not appear to obey known laws of physics, scientists announced Wednesday, a discovery that would open a large and torturous hole in our understanding of the universe.

The results, physicists say, suggest that there are forms of matter and energy vital to the nature and evolution of the cosmos that are not yet known to science.

“This is the moment of our landing from Mars rover,” said Chris Polly, a physicist from Fermi’s National Acceleration Laboratory or Fermilab of Batavia in Illinois, who has spent most of his career working on this discovery.

The particle célèbre is a 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 the muons did not behave as predicted when they fired through the intense magnetic field at Fermilab.

Aberrant behavior poses a solid challenge to the Standard Model, a set of equations that enumerates elementary particles in space (17, eventually calculated) and how they interact.

“This is strong evidence that muon is sensitive to something that is not in our best theory,” said Renee Fatemi, a physicist at the University of Kentucky.

Update: In Quanta magazine, Natalie Wolchover dives deeper into the preliminary results and what they might mean.

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