An Etymological Dictionary of Astronomy and Astrophysics

An → elementary particle with zero → charge, → spin 1/2, and very small → rest mass. The three types of neutrino (electron neutrino, muon neutrino, tau neutrino) experience only the → weak nuclear force and gravitational force, and pass easily through matter.

The neutrino undergoes a quantum mechanical phenomenon in which → neutrino flavor changes spontaneously to another flavor (→ neutrino oscillation). The neutrino was first postulated by Wolfgang Pauli in 1931 to account for the problem of energy → conservation in → beta decay. It was discovered in 1956.
See also:

→ antineutrino, → atmospheric neutrino, → cosmic neutrino background (CNB), → cosmogenic neutrino, → high-energy neutrino, → low-energy neutrino, → solar neutrino, → solar neutrino problem, → solar neutrino unit (SNU), → sterile neutrino, → ultra-high-energy neutrino.

See also: Neutrino, coined by Enrico Fermi (1901-1954), from neutr(o)→ neuter + -ino diminutive suffix.