antineutrino

physics

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June 18, 2026

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An antineutrino is an elementary subatomic particle that is the antiparticle of the neutrino. Like the neutrino, it has no electric charge and very little mass, and it is subject to the weak force. The key difference is its spin direction; an antineutrino spins clockwise when viewed from behind, whereas a neutrino spins counterclockwise.12

Antineutrinos are produced in certain types of radioactive decay, such as beta decay. They were first experimentally detected in 1956, produced in nuclear reactors. A particle and its antiparticle, like a neutrino and antineutrino, can annihilate each other, producing energy.21

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principles of physical science
Development of the atomic theory
…of a positron and an antineutrino. For example, a magnesium nucleus containing 12 protons and 11 neutrons spontaneously changes to a stable sodium nucleus with 11 protons and 12 neutrons. The positron resembles the electron in all respects except for being positively rather than negatively charged. It was the first…
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…of a positron and an antineutrino. For example, a magnesium nucleus containing 12 protons and 11 neutrons spontaneously changes to a stable sodium nucleus with 11 protons and 12 neutrons. The positron resembles the electron in all respects except for being positively rather than negatively charged. It was the first…
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subatomic particle
Antiparticles
Indeed, it is an antineutrino, rather than a neutrino, that emerges when a neutron changes by beta decay into a proton. This reflects an empirical law regarding the production and decay of quarks and leptons: in any interaction the total numbers of quarks and leptons seem always to remain…
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Indeed, it is an antineutrino, rather than a neutrino, that emerges when a neutron changes by beta decay into a proton. This reflects an empirical law regarding the production and decay of quarks and leptons: in any interaction the total numbers of quarks and leptons seem always to remain…
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subatomic particle
Neutral leptons (neutrino)
…of the muon’s decay, the antineutrino produced is not simply the antiparticle of the neutrino that appears with it. The neutrino carries a muon-type hallmark, while the antineutrino, like the antineutrino emitted when a neutron decays, is always an electron-antineutrino. In interactions with matter, such electron-neutrinos and antineutrinos never produce…
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…of the muon’s decay, the antineutrino produced is not simply the antiparticle of the neutrino that appears with it. The neutrino carries a muon-type hallmark, while the antineutrino, like the antineutrino emitted when a neutron decays, is always an electron-antineutrino. In interactions with matter, such electron-neutrinos and antineutrinos never produce…
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radiation
Neutrinos and antineutrinos
Neutrinos and their antiparticles are forms of radiation similar to electromagnetic rays in that they travel at the speed of light and have little or no rest mass and zero charge. They too are produced by ultrahigh-energy particle accelerators and certain types of radioactive…
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Neutrinos and their antiparticles are forms of radiation similar to electromagnetic rays in that they travel at the speed of light and have little or no rest mass and zero charge. They too are produced by ultrahigh-energy particle accelerators and certain types of radioactive…
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