lepton

There are patterns seen in quarks and leptons that remain unexplained, but it can be hypothesized that quarks and leptons might be created of still smaller particles. Does the Standard Model allow for an even smaller layer of matter to exist?

The Mu2e experiment at Fermilab will look for a never-before-seen subatomic phenomenon that, if observed, would transform our understanding of elementary particles: the direct conversion of a muon into an electron. An international collaboration of over 200 scientists is building the Mu2e precision particle detector that will hunt for new physics beyond the Standard Model.

Building experimental evidence suggests that the electron, muon and tau may feel different forces.