tauons

• third-generation charged lepton: 1.777 GeV/c², ~3500× the electron mass (~1.9 proton masses)
• lifetime ≈ 2.9 × 10⁻¹³ s
• the only lepton heavy enough to decay into hadrons (~65% of decays), useful for studying the strong interaction
• tau neutrino: first directly detected in 2000 (DONUT, Fermilab)