Editing Truly neutral particle

{{Short description|Particle that is its own antiparticle because all of its generalized charges are zero}}
In [[particle physics]], a '''truly neutral particle''' is a [[subatomic particle]] that has no charge quantum number; they are their own [[antiparticle]].<ref name=Okun-1985>{{cite book
 |last=Okun |first=L.B.
 |year=1985
 |title=Particle Physics: The quest for the substance of substance
 |publisher=[[CRC Press]]
 |isbn=978-3-7186-0228-5
 |page=131
 |url=https://books.google.com/books?id=UBidG9OKrQ8C&pg=PA131
 |via=Google Books
}}
</ref>{{rp|131}}
In other words, it remains itself under the [[C-symmetry|charge conjugation]], which replaces [[particle]]s with their corresponding antiparticles.<ref name=Okun-1985/>{{rp|135}} All [[charge (physics)|charges]] of a ''truly neutral particle'' must be equal to [[zero]]. This requires particles to not only be [[electric charge|electrically]] [[Neutral particle|neutral]], but also requires that all of their other charges (such as the [[colour charge]]) be neutral.

==Examples==
Known examples of such elementary particles include [[photon]]s, [[Z boson]]s, and [[Higgs boson]]s, along with the hypothetical [[neutralino]]s, [[sterile neutrino]]s, and [[graviton]]s. For a [[spin-½]] particle such as the neutralino, being ''truly neutral'' implies being a [[Majorana fermion]].

By way of contrast, neutrinos are not ''truly neutral'' since they have a [[weak isospin]] of {{sfrac|±|1|2}}, or equivalently, a non-zero [[weak hypercharge]], both of which are charge-like quantum numbers. 

==References==
{{reflist}}

== Further reading ==
* {{cite book
 |last=Davydov |first=A.S.
 |year=1976
 |title=Quantum Mechanics  |edition=2nd
 |publisher=[[Pergamon Press]]
 |isbn=978-1-4831-8783-9
 |page=218
 |url=https://books.google.com/books?id=rLE3BQAAQBAJ&pg=PA218
 |via=Google Books
}}

[[Category:Particle physics]]

{{Particle-stub}}