Quark Model Classification
In the quark model with SU(2) flavour, the two nucleons are part of the ground state doublet. The proton has quark content of uud, and the neutron, udd. In SU(3) flavour, they are part of the ground state octet (8) of spin 1⁄2 baryons, known as the Eightfold way. The other members of this octet are the hyperons strange isotriplet Σ+, Σ0, Σ−, the Λ and the strange isodoublet Ξ0, Ξ−. One can extend this multiplet in SU(4) flavour (with the inclusion of the charm quark) to the ground state 20-plet, or to SU(6) flavour (with the inclusion of the top and bottom quarks) to the ground state 56-plet.
The article on isospin provides an explicit expression for the nucleon wave functions in terms of the quark flavour eigenstates.
Read more about this topic: Nucleon
Famous quotes containing the word model:
“... if we look around us in social life and note down who are the faithful wives, the most patient and careful mothers, the most exemplary housekeepers, the model sisters, the wisest philanthropists, and the women of the most social influence, we will have to admit that most frequently they are women of cultivated minds, without which even warm hearts and good intentions are but partial influences.”
—Mrs. H. O. Ward (1824–1899)