| Composition | Elementary particle |
|---|---|
| Statistics | Fermionic |
| Generation | Third |
| Interactions | Weak, Gravity |
| Symbol | ν τ |
| Antiparticle | Tau antineutrino ( ν τ) |
| Theorized | Mid 1970s |
| Discovered | DONUT collaboration (2000) |
| Mass | Very small but not zero. (See neutrino mass.) |
| Electric charge | 0 e |
| Color charge | No |
| Spin | 1/2 |
| Weak isospin | 1/2 |
| Weak hypercharge | −1 |
| Chirality | left-handed (for right-handed neutrinos, see sterile neutrino) |
The tau neutrino or tauon neutrino is a subatomic elementary particle which has the symbol
ν
τ and no net electric charge. Together with the tau (τ), it forms the third generation of leptons, hence the name tau neutrino. Its existence was immediately implied after the tau particle was detected in a series of experiments between 1974–1977 by Martin Lewis Perl with his colleagues at the SLAC–LBL group.[1] The discovery of the tau neutrino was announced in July 2000 by the DONUT collaboration (Direct Observation of the Nu Tau).[2][3]
Discovery
The tau neutrino is last of the leptons, and is the second most recent particle of the Standard Model to be discovered. The DONUT experiment from Fermilab was built during the 1990s to specifically detect the tau neutrino. These efforts came to fruition in July 2000, when the DONUT collaboration reported its detection.[2][3]
See also
- Electron neutrino
- Muon neutrino
- PMNS matrix
References
- ^ Perl, M.L.; et al. (1975). "Evidence for anomalous lepton production in
e+
e−
annihilation". Physical Review Letters. 35 (22): 1489. Bibcode:1975PhRvL..35.1489P. doi:10.1103/PhysRevLett.35.1489. - ^ a b Jackson, Judy; et al. (20 July 2000). "Physicists find first direct evidence for tau neutrino at Fermilab" (Press release). Batavia, IL: Fermilab.
- ^ a b Kodama, K.; et al. (DONUT collaboration) (2001). "Observation of tau neutrino interactions". Physics Letters B. 504 (3): 218–224. arXiv:hep-ex/0012035. Bibcode:2001PhLB..504..218D. doi:10.1016/S0370-2693(01)00307-0.