Editing Eightfold way (physics) (section)

===Mesons===
In the original eightfold way, the mesons were organized into octets and singlets. This is one of the finer points of differences between the eightfold way and the quark model it inspired, which suggests the mesons should be grouped into nonets (groups of nine).

====Meson octet====
[[Image:meson octet.png|thumb|The [[pseudoscalar meson]] octet]]
The eightfold way organizes eight of the lowest [[Spin (physics)|spin]]-0 [[meson]]s into an octet.<ref name=Gell-Mann-1961-TID-12608/><ref name=Gell-Mann-1962/> They are:
* {{SubatomicParticle|Kaon0}}, {{SubatomicParticle|Kaon+}}, {{SubatomicParticle|Kaon-}} and {{SubatomicParticle|AntiKaon0}} [[kaon]]s
* {{SubatomicParticle|pion+}}, {{SubatomicParticle|pion0}}, and {{SubatomicParticle|pion-}} [[pion]]s
* {{SubatomicParticle|eta}}, the [[eta meson]]

Diametrically opposite particles in the diagram are [[anti-particle]]s of one another, while particles in the center are their own anti-particle.

====Meson singlet====
The chargeless, strangeless eta prime meson was originally classified by itself as a singlet:
* [[Eta meson|{{SubatomicParticle|eta prime}}]]

Under the quark model later developed, it is better viewed as part of a meson nonet, as previously mentioned.