Antineutrino
From Wikipedia, the free encyclopedia
| Antineutrino | |
| Composition: | Elementary particle |
|---|---|
| Family: | Fermion |
| Group: | Lepton |
| Interaction: | weak force and gravity |
| Antiparticle: | Neutrino |
| Theorized: | 1930 |
| Discovered: | 1956 |
| Symbol: |  ,  and  |
| No. of types: | 3 - electron, muon and tau |
| Electric charge: | 0 |
| Color charge: | 0 |
| Spin: | 1/2 |
In physics, antineutrinos, the antiparticles of neutrinos, are neutral particles produced in nuclear beta decay. They have a spin of 1/2, and they are part of the lepton family of particles. The antineutrinos observed so far all have right-handed helicity (i.e., only one of the two possible spin states is realized), while the neutrinos are left-handed. Antineutrinos interact with other matter only through the gravitational and weak forces, making them very difficult to detect experimentally. Neutrino oscillation experiments indicate that antineutrinos have mass, but beta decay experiments constrain that mass to be very small.
Because antineutrinos and neutrinos are neutral particles it is possible that they are actually the same particle. Particles which have this property are known as Majorana particles. If neutrinos are indeed Majorana particles then the neutrinoless double beta decay process is allowed. Several experiments have been proposed to search for this process.
[edit] See also
[edit] External links
|
|
|
| Fermions: Quarks: (Up · Down · Strange · Charm · Bottom · Top) | Leptons: (Electron · Muon · Tau · Neutrinos) | |
| Gauge bosons: Photon | W and Z bosons | Gluons | |
| Not yet observed: Higgs boson | Graviton | Other hypothetical particles | |
