a hypothetical type of neutrino that would obey a conservation law together with the tau lepton, with the total number of tau leptons and tau neutrinos minus the total number of their antiparticles remaining constant.
(tou, tô) A type of neutrino associated with the tau particle, often created in particle interactions involving tau particles (such as the decay of these particles). The tau neutrino has a mass of zero or near zero, and has no electric charge. See more at neutrino. See Table at subatomic particle.