Beta decay
![β− decay in an atomic nucleus (the accompanying antineutrino is omitted). The inset shows beta decay of a free neutron. In both processes, the intermediate emission of a virtual W− boson (which then decays to electron and antineutrino) is not shown.](/Images/godic/202412/24/Beta-minus_Decay.svg0936.png")
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![The Feynman diagram for β− decay of a neutron into a proton, electron, and electron antineutrino via an intermediate W− boson.](/Images/godic/202412/24/Beta_Negative_Decay.svg0936.png")
![A beta spectrum, showing a typical division of energy between electron and antineutrino](/Images/godic/202412/24/RaE10936.jpg")
In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a proton is transformed into a neutron, or vice versa, inside an atomic nucleus. This process allows the atom to move closer to the optimal ratio of protons and neutrons. As a result of this transformation, the nucleus emits a detectable beta particle, which is an electron or positron.