an elementary particle that participates in weak interactions but does not participate in the strong interaction; it has a baryon number of 0. Some known leptons are the electron, the negative muon, the tau-minus particle, and the neutrinos associated with each of these particles.
The fundamental matter particles that do not carry color charge. They are all spin / particles, and include the electron, muon, tau, and their corresponding neutrinos. See also: fundamental particle, spin, electron, neutrino, Debriefing
Along with q uarks, leptons make up all known matter. Unlike quarks, leptons do not participate in strong interactions. Neutrinos and electrons are two common examples. There are three flavors of leptons: electron, muon, and tau.