ax·​ion | \ ˈak-sē-(ˌ)än How to pronounce axion (audio) \

Definition of axion

: a hypothetical subatomic particle of low mass and energy that is postulated to exist because of certain properties of the strong force

Examples of axion in a Sentence

Recent Examples on the Web The Sun could be producing a novel type of (candidate dark matter) particle known as an axion. Ethan Siegel, Forbes, 27 Apr. 2021 Live Science shared the XENON collaboration’s press release with two axion experts. Rafi Letzter, Scientific American, 17 June 2020 This is the shape of the mathematical function defining the axion field. Quanta Magazine, 17 Mar. 2020 The new idea, which goes by the name axiogenesis, could further motivate experimental searches for the axion. Quanta Magazine, 17 Mar. 2020 To demonstrate their idea, Jiang and Wilczek focused on an unorthodox set of rules called axion electrodynamics, which could give rise to unique properties. Quanta Magazine, 25 Sep. 2018 Wilczek came up with the theory in 1987 to describe how a hypothetical particle called an axion would interact with electricity and magnetism. Quanta Magazine, 25 Sep. 2018 Enter the axion, the second-most promising candidate for dark matter. Jennifer Ouellette, Ars Technica, 17 Oct. 2019 The hunt for wispy particles called axions, which might make up the dark matter whose gravity keeps galaxies from falling apart, is heating up. Adrian Cho, Science | AAAS, 9 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'axion.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of axion

1978, in the meaning defined above

History and Etymology for axion

axi(al) + -on entry 2

Note: The name axion was introduced by the American physicist Stephen Weinberg (born 1933) in "A New Light Boson?", Physical Review Letters, vol. 40, no. 4 (January 23, 1978), p. 233; and by American physicist Frank Wilczek (born 1951) in "Problems of Strong P and T Invariance in the Presence of Instantons," Physical Review Letters, vol. 40, no. 5, p. 279. In an article in the on-line journal Quanta, "Time's (Almost) Irreversible Arrow" (January 7, 2016), Frank Wilczek explained the coinage as follows: "A few years before [in 1977], a supermarket display of brightly colored boxes of a laundry detergent named Axion had caught my eye. It occurred to me that 'axion' sounded like the name of a particle and really ought to be one. So when I noticed a new particle that 'cleaned up' a problem with an 'axial' current, I saw my chance. (I soon learned that Steven Weinberg had also noticed this particle, independently. He had been calling it the 'Higglet.' He graciously, and I think wisely, agreed to abandon that name.) Thus began a saga whose conclusion remains to be written."

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Last Updated

9 May 2021

Cite this Entry

“Axion.” Dictionary, Merriam-Webster, Accessed 15 Jun. 2021.

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