axion

noun

ax·​ion ˈak-sē-(ˌ)än 

: 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

No WIMPs, no axions—just a slight tweak to some century-old equations. —Dan Falk, Smithsonian Magazine, 25 Oct. 2024

Like WIMPs, axions are thought to have been produced in the very early universe. —Dan Falk, Smithsonian Magazine, 25 Oct. 2024

If dark matter is made up of wavelike particles called axions, then the varying density of axions from place to place should cause the strength of some of the forces to wiggle up and down. —Quanta Magazine, 4 Sep. 2024

As the efforts continue to rule out various WIMP candidates, interest is surging in another idea: that dark matter consists of axions. —Saima S. Iqbal, Scientific American, 8 Aug. 2024

Word History

Etymology

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 online 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."

First Known Use

1978, in the meaning defined above