beta (b ) decay Process of nuclear disintegration, in which a neutron rich nucleus decays producing an electron (beta particle). Hence the name beta decay. In addition, particle known as neutrino n _e is always one of the decay products. An example of neutron beta decay,

₅B¹² ® ₆C¹² + e^- + n _e

n represents the anti neutrino (i.e. anti particle of neutrino).

The final reaction can be written as,

n ® p + e^- + n _e

where n represents the neutron that converts itself into a proton. There are two similar processes. One such process is b ⁺ decay. An example of b ^* decay is,

The other is called electron capture process. An example of electron capture process is,

e^- + ₄Be⁷ ® ₃Li⁷ + n

The existence of neutrino was first proposed by W. Pauli in 1930, in order to preserve the conservation of energy and momentum in beta decay. The neutrino has charge 0, rest mass 0, intrinsic spin 1/2 and travels with speed of light (See also elementary particles).