Lepton

English

Noun

1. A fermion that has 1/2 spin and is immune to the strong nuclear force. Most are extremely light particles, but the tauon is a notable exception being twice as heavy as a proton. All leptons have a negatively charged particle and a positively charged antiparticle, as well as a related neutrino and antineutrino of neutral charge. Members are the electron, the muon and the tauon .