antiparticle

American  

[an-tee-pahr-ti-kuhl, an-tahy-] / ˈæn tiˌpɑr tɪ kəl, ˈæn taɪ- /

noun

Physics.

1. a particle all of whose properties, as mass, spin, or charge, have the same magnitude as but, where appropriate, the opposite sign of a specific elementary particle; neutral pions, photons, and gravitons are considered to be their own antiparticles.

   The positron is the antiparticle of the electron.

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antiparticle British  

/ ˈæntɪˌpɑːtɪkəl /

noun

1. any of a group of elementary particles that have the same mass and spin as their corresponding particle but have opposite values for all other nonzero quantum numbers. When a particle collides with its antiparticle, mutual annihilation occurs

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antiparticle Scientific  

/ ăn′tē-pär′tĭ-kəl,ăn′tī- /

1. A subatomic particle, such as an antiproton, having the same mass as its corresponding particle, but opposite values of other properties such as charge, parity, spin, and direction of magnetic moment. For example, the antiparticle of the electron is the positron, which has a charge that is equal in magnitude to that of the electron but opposite in sign. Some particles, such as photons, are nondistinct from their antiparticles. When a particle and its antiparticle collide, they may annihilate one other and produce other particles.

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antiparticle Cultural  

1. In physics, a rare form of subatomic matter that is a mirror image of normal matter. The antiparticle corresponding to an elementary particle has the same mass as the particle but is opposite in all other properties. The antiparticle corresponding to an electron is a positron, which has the same mass as an electron but a positive charge. Antiprotons have the same mass as protons but a negative charge. When matter and antimatter come together, the two particles annihilate each other, converting their mass into energy or into other types of particles.

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Discover More

As far as scientists can tell, there is almost no naturally occurring antimatter in the universe, although it is possible to make antimatter in particle accelerators.

Etymology

Origin of antiparticle

First recorded in 1930–35; anti- + particle

Example Sentences

A muon collider would smash high-energy muons—heavier, unstable cousins of electrons—into their antiparticles in two huge particle detectors.

From Science Magazine • Mar. 27, 2024

"The stability and binding properties of positronic compounds provide unique perspectives on the interaction of antiparticles with ordinary substances, paving the way for novel investigations in the field of quantum chemistry," remarks Dr. Tachibana.

From Science Daily • Oct. 10, 2023

Some physicists have speculated that antiparticles are being repelled by gravity or even traveling backward in time.

From New York Times • Sep. 27, 2023

He compares this with the notion introduced by British physicist Paul Dirac in the 1920s who argued particles possess antiparticles, and if brought together, a particle and antiparticle can annihilate each other.

From Scientific American • May 21, 2018

The question of why there seem to be so many more particles than antiparticles around us is extremely important, and I shall return to it later in the chapter.

From "A Brief History of Time: And Other Essays" by Stephen Hawking