Editing Hadron (section)

==Baryons==
{{Main|Baryon|Exotic baryon}}

[[Baryon]]s are hadrons containing an odd number of valence quarks (at least 3).<ref name=GellMann-1964/> Most well-known baryons such as the [[proton]] and [[neutron]] have three valence quarks, but [[pentaquark]]s with five quarks—three quarks of different colors, and also one extra quark-antiquark pair—have also been proven to exist. Because baryons have an odd number of quarks, they are also all [[fermion]]s, ''i.e.'', they have half-integer [[Spin (physics)|spin]]. As quarks possess [[baryon number]] ''B''&nbsp;=&nbsp;{{frac|1|3}}, baryons have baryon number ''B''&nbsp;=&nbsp;1. Pentaquarks ''also'' have ''B''&nbsp;=&nbsp;1, since the extra quark's and antiquark's baryon numbers cancel.

Each type of baryon has a corresponding antiparticle (antibaryon) in which quarks are replaced by their corresponding antiquarks. For example, just as a proton is made of two up quarks and one down quark, its corresponding antiparticle, the antiproton, is made of two up antiquarks and one down antiquark.

As of August 2015, there are two known pentaquarks, {{nowrap|P{{su|p=+|b=c}}(4380)}} and {{nowrap|P{{su|p=+|b=c}}(4450)}}, both discovered in 2015 by the [[LHCb]] collaboration.<ref name=Aaij-etal-2015-LHCb-Jψp/>