The lepton epoch follows a similar path to the earlier hadron epoch. The amount of matter is defined in terms of baryon and lepton number. In modern terminology, this makes the muon a lepton, and not a meson. The tau lepton is predicted to form exotic atoms like other charged subatomic particles. Due to its mass, it was initially categorized as a meson rather than a lepton. CP violation in the lepton sector generates a matter-antimatter asymmetry through a process called leptogenesis. CLIC examines the feasibility of a high-energy (up to 3 TeV), high-luminosity lepton (electron/positron) collider. Some of these lepton colliders are still running. Neutrinoless double beta decay is a lepton number violating process. The charged lepton generates a visible "optical shockwave" of Cherenkov radiation. The prize was awarded "for pioneering experimental contributions to lepton physics". It consisted of seven denominations (1 lepton, 2, 5, 10, 20, 40 and 80 lepta). The third contained only the 1 lepton, 2, 5, 40 and 60 lepta. This fact is true for all lepton interactions in The Standard Model. It confirmed the existence of the last lepton predicted by the Standard Model.