Beta particle

Beta particles are high-energy electrons emitted by certain types of radioactive nuclei such as potassium-40. The beta particles emitted are a form of ionizing radiation also known as beta rays. The production of beta particles is termed beta decay. They are designated by the Greek letter beta (β).

β⁺ decay (positron)

Unstable nuclei that are deficient in neutrons may undergo β+ decay, where a proton is converted into a neutron. The proton consists of two up quarks and a down quark, one of the proton's up quarks decays to a down quark, doing so, it will emit a W particle, which is unstable and decays further into a positron, and an electron neutrino:

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mbox{p} ightarrow mbox{n} + mbox{e}^+ + u_{e}

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The positron and the neutrino are emitted from the nucleus.

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mbox{p(uud)} ightarrow mbox{n(udd)} + mbox{W}^+ ightarrow mbox{e}^+ + u_{e}

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