Beta Radiactive Decay
A type of radioactive decay, noted β, in which a beta particle (an electron or a positron) is emitted. If an electron (a negatively charged particle) is emitted, the emission is called beta minus (β–) decay; if a positron (a positively charged particle) is emitted, the emission is called beta plus (β+) decay. The weak interaction is at the origin of this form of radioactivity. For instance, a neutron turns into a proton by emitting an electron and an antineutrino.