Editing Axion (section)

{{Short description|Hypothetical elementary particle}}
{{hatnote group|
{{Distinguish|axiom|axon}}
{{Other uses}}
}}
{{Infobox particle
| name = Axion
| composition =
| status = Hypothetical
| interaction = [[Gravitational]], [[Electromagnetic interaction|electromagnetic]], [[Strong interaction|strong]], [[Weak interaction|weak]]
| theorized = 1978, [[Frank Wilczek|Wilczek]] and [[Steven Weinberg|Weinberg]]
| symbol = A<sup>0</sup>, a, θ
| mass = 10<sup>−5</sup> to 1&nbsp;[[electronvolt|eV]]/[[Speed of light|''c'']]<sup>2</sup>{{spaces|1}}<ref name="peccei2008">{{cite book|last=Peccei | first=R. D. | title=Axions: Theory, Cosmology, and Experimental Searches <!-- leave subtitle --> |year=2008 |chapter=The Strong CP Problem and Axions |editor1-last=Kuster |editor1-first=Markus |editor2-last=Raffelt |editor2-first=Georg |editor3-last=Beltrán |editor3-first=Berta |series=Lecture Notes in Physics |volume=741 |pages=3–17 |arxiv=hep-ph/0607268 |doi=10.1007/978-3-540-73518-2_1 |isbn=978-3-540-73517-5|s2cid=119482294 }}</ref>
| electric_charge = 0&nbsp;''e''
| spin = 0&nbsp;''ħ''
<!-- | Grouping = [[Goldstone Boson]] -->
}}

An '''axion''' ({{IPAc-en|ˈ|æ|k|s|i|ɒ|n}}) is a hypothetical [[elementary particle]] originally theorized in 1978 independently by [[Frank Wilczek]] and [[Steven Weinberg]] as the [[Goldstone boson]] of [[Peccei–Quinn theory]], which had been proposed in 1977 to solve the [[strong CP problem]] in [[quantum chromodynamics]] (QCD). If axions exist and have low mass within a specific range, they are of interest as a possible component of [[cold dark matter]].