Selection rules and quark correlations in the $N^*$ resonance spectrum

Qiang Zhao, Frank E. Close

Published 2007-11-01Version 1

A "$\Lambda$ selection rule" for $N^*$ resonances in the presence of QCD mixing effects is identified. Due to the QCD mixing, excitations of {\bf 20}-plets are possible in SU(6). We show that this selection rule is useful for classifying PDG states at N=2, and for clarifying whether strongly correlated diquarks survive for $L > 0$.