The
tau (t), also called the
tau lepton,
tau particle, or
tauon, is an
elementary particle similar to the electron, with negative
electric charge and a . Together with the
electron, the
muon, and the three
neutrinos, it is a
lepton. Like all elementary particles with half-integral spin, the tau has a corresponding
antiparticle of opposite charge but equal
mass and spin, which in the tau's case is the
antitau (also called the
positive tau). Tau particles are denoted by and the antitau by .