beta decay

American  

noun

Physics.

1. a radioactive process in which a beta particle is emitted from the nucleus of an atom, raising the atomic number of the atom by one if the particle is negatively charged, lowering it by one if positively charged.

---

beta decay British  

noun

1. Also called: beta transformation.   beta process.  the radioactive transformation of an atomic nucleus accompanying the emission of an electron. It involves unit change of atomic number but none in mass number

---

beta decay Scientific  

1. A form of radioactive decay caused by the weak nuclear force, in which a beta particle (electron or positron) is emitted.

2. ◆ In beta-minus decay, a neutron in an atomic nucleus decays into a proton, an electron, and an antineutrino. The electron and antineutrino are emitted from the nucleus, while the proton remains. The atomic number of the atom is thereby increased by 1. The decay of Carbon-14 into Nitrogen-14, a phenomenon useful in carbon dating, is an example of beta-minus decay.

3. ◆ In beta-plus decay, a proton in an atomic nucleus decays into a neutron, a positron, and a neutrino. The positron and neutrino are emitted from the nucleus, while the neutron remains. The atomic number of the atom is thereby reduced by 1. The decay of Carbon-10 to Boron-10 is an example of beta-plus decay.

4. See also W boson

---

Etymology

Origin of beta decay

First recorded in 1930–35

Example Sentences

Along this pathway across the nuclide chart, a common sequence involves beta decay of the parent nucleus followed by the release of two neutrons.

From Science Daily • Mar. 13, 2026

Traditionally, scientists believed the tin nucleus simply released neutrons to cool down, effectively losing any trace of the earlier beta decay event.

From Science Daily • Mar. 13, 2026

If neutrinoless double beta decay is ever observed it would indicate that the neutrino is its own antiparticle, unlike any other fundamental particle that has mass.

From Science Magazine • Aug. 22, 2023

Yang and Lee's hypothesis, though, suggested that the behavior of nuclear particles in beta decay might not look the same if you flipped the events in an imaginary mirror.

From Scientific American • Mar. 16, 2023

This is different from beta decay, in which a neutron is transformed into a proton by the emission of an electron.

From "Big Science" by Michael Hiltzik