Contrary to what the name might suggest, the neutrino (denoted by the Greek letter ν)
is not a kind of mini-neutron, but a particle that is closely related to the electron.
Like the neutron, the neutrino has no
charge, but its
mass is about a billion times smaller than that of the neutron.
The neutrino hardly interacts with
matter.
The half-value thickness of water for 1 MeV neutrinos is 1019 m,
which is the unimaginably far distance light travels in 10,000 years.
History
The neutrino was postulated in 1930 by the Austrian physicist Wolfgang Ernst Pauli
(1900 - 1958). Its existence was first demonstrated in 1956 by the American physicists
Clyde Lorraine Cowan (1919 - 1974) and Frederick Reines (1918 - 1998).
History
The name is the Italian equivalent of "little neutral one" and was jokingly coined
in order to distinguish this light neutral particle from the heavy neutron.
