antihelium-4

physics

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July 20, 2026

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Antihelium is the antimatter counterpart of helium. Antimatter is composed of subatomic particles with opposite electric charges and magnetic moments compared to ordinary matter. For example, an antiproton has a negative charge, unlike a proton's positive charge.123

When matter and antimatter come into contact, they annihilate each other, releasing significant energy. Antihelium-4, consisting of two antiprotons and two antineutrons, has been created in particle accelerators. Despite theoretical predictions that matter and antimatter should be created in equal amounts, the observable universe appears to be dominated by matter, a puzzle known as matter-antimatter asymmetry.2

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antimatter
…heaviest antiatom, the nucleus of antihelium-4, which consists of two antiprotons and two antineutrons. Since antihelium-4 is produced so rarely in nuclear collisions, its detection in space by an instrument such as the Alpha Magnetic Spectrometer on the International Space Station would imply the existence of large amounts of antimatter…
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…heaviest antiatom, the nucleus of antihelium-4, which consists of two antiprotons and two antineutrons. Since antihelium-4 is produced so rarely in nuclear collisions, its detection in space by an instrument such as the Alpha Magnetic Spectrometer on the International Space Station would imply the existence of large amounts of antimatter…
Read More