is an elementary subatomic particle with infinitesimal mass
(less than 0.3 eV..?) and with no electric charge
. Neutrinos belong to the family of leptons, which means they do not interact via strong nuclear force
. Neutrinos are weakly interacting
subatomic particles with ½ unit of spin. The term neutrino comes from Italian meaning “little neutral one” and neutrinos are denoted by the Greek letter ν (nu)
. There are three types of charged leptons, each associated with neutrino, forming three generations
(between generations, particle differ by their quantum number and mass). The first generation consist of the electron (e−
) and electron-neutrino (νe
). The second generation consist of the muon (μ−
) and muon neutrino (νμ
) The third generation consist of the tau (τ−
) and the tau neutrino (ντ
). Each type of neutrino is associated with an antimatter particle, called an antineutrino
, which also has neutral electric charge and 1/2 spin. Currently (2015), it is not resolved, whether the neutrino and its antiparticle are not identical particles.
Carrying no electric charge they are not affected by electromagnetic forces that act on another charged leptons, such as electrons. Since neutrinos belong to the family of leptons, they are not subject to the strong force. Neutrinos are subject to the weak force, which is of much shorter range than electromagnetic force and gravity force. Therefore, neutrinos are the most penetrating subatomic particles, capable of passing through Earth without any interaction. It is estimated neutrinos have interaction cross-sections about 20 orders of magnitude less than typical cross-sections of scattering of two nucleons (~10-47m2 = 10-19barn). It is estimated neutrino cross-section for interaction increases linearly with energy of incident neutrino.
Reference: Griffiths, David, Introduction to Elementary Particles, Wiley, 1987.
See also: Antineutrino
See also: Nuclear Reactor as the Antineutrino Source