kaon

noun

ka·​on ˈkā-ˌän How to pronounce kaon (audio)
: an unstable meson that occurs in both charged and neutral forms and is about 970 times more massive than an electron

Examples of kaon in a Sentence

Recent Examples on the Web
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The detection challenge is to sort deuterons and antideuterons from other subatomic particles, such as pions, protons, and kaons, and to measure momenta precisely enough to observe femtoscopic correlations. Tejasri Gururaj, Interesting Engineering, 29 Jan. 2026 The kaons then fly down a roughly 150-meter-long vacuum tunnel. Clara Moskowitz, Scientific American, 1 Oct. 2024 The kaon, a special case of meson particle, is made of one quark and one antiquark. Caroline Delbert, Popular Mechanics, 6 Mar. 2020 This symmetry would be all well and good if physicists had not discovered in 1964 that the weak nuclear force doesn’t share it: Two-quark particles called neutral kaons decay in ways CP symmetry forbids. Quanta Magazine, 27 Nov. 2019 The Xi decays into a particle called the lambda baryon and three lighter particles, the K- (or kaon) and two pions. Fox News, 11 July 2017 The most famous of these two-quark particles are kaons and pions. Adam Mann, WIRED, 17 June 2013

Word History

Etymology

International Scientific Vocabulary ka kay (from K-meson, its earlier name) + -on entry 2

First Known Use

1958, in the meaning defined above

Time Traveler
The first known use of kaon was in 1958

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Cite this Entry

“Kaon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/kaon. Accessed 9 Feb. 2026.

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