Phenomenology of the baryon resonance 70-plet at large Nc

We examine the multiplet structure and decay channels of baryon resonances in the large Nc QCD generalization of the Nc=3 SU(6) spin-flavor 70. We show that this "70," while a construct of large Nc quark models, actually consists of five model-independent irreducible spin-flavor multiplets in the large Nc limit. The preferred decay modes for these resonances fundamentally depend upon which of the five multiplets to which the resonance belongs. For example, there exists an SU(3) "8" of resonances that is η-philic and π-phobic, and an "8" that is the reverse. Moreover, resonances with a strong SU(3) "1" component prefer to decay via a K̄ rather than via a π. Remarkably, available data appears to bear out these conclusions.