Each type of neutrino has its own antiparticle.Īccording to the so-called oscillation theory, neutrinos can change from one type to another as they travel through space in order to make these transformations, neutrinos have to have a tiny amount of mass and not be massless, as was originally theorized. A third type, the tau neutrino, associated with the tau particle, was identiified in the mid-1970s but not detected until 2000. In 1962 it was found that the neutrino associated with the muon (the muon neutrino) is distinct from that associated with the electron (the electron neutrino). Cowan recognized them by their impact with subnuclear particles in mineral water.

The neutrino was not detected directly until 1956, when American physicists Frederick Reines and Clyde L. Neutrinos are stable and can be absorbed only by the same weak interactions through which they are created an energetic neutrino can induce the reverse of the decay that produced it. Neutrinos are also emitted when a pion decays into a muon and in the decays of a number of other elementary particles. Like the electron, the neutrino is a lepton it participates only in the weak decay of nuclear particles and has no role in the strong force binding nuclei together. Further studies showed that the neutrino was also necessary to maintain the conservation laws of momentum and spin. Moreover, if it were charged, the law of conservation of charge would be violated during beta decay. Its charge must be zero because a charged particle would easily be detected. Pauli suggested that when the electron has less than the maximum possible value, the remaining energy is carried away by an undetected particle, the neutrino. When a radioactive nucleus emits a beta particle (electron), the electron may have any energy from zero up to a certain maximum. The neutrino was first postulated in 1930 by Wolfgang Pauli in order to maintain the law of conservation of energy during beta decay (see conservation laws radioactivity). Neutrino no͞otrē´nō, elementary particle with no electric charge and a very small mass emitted during the decay of certain other particles.

Neutrino particle