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

TL;DR

This paper introduces a selection rule for N* resonances considering QCD mixing effects, aiding in classifying states and understanding quark correlations in the spectrum.

Contribution

It identifies a new selection rule applicable to N* resonances with QCD mixing, enhancing classification and insight into diquark correlations.

Findings

Selection rule helps classify N* states at N=2

QCD mixing allows excitations of 20-plets in SU(6)

Clarifies the persistence of diquark correlations for L > 0

Abstract

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 $L > 0$.