Excited Baryons in Large Nc QCD: Matching the 1/Nc expansion to quark models using the permutation group S_N

TL;DR

This paper develops a method to connect quark models with the 1/Nc expansion of QCD, focusing on excited baryon masses and their relation to different quark interaction models.

Contribution

It introduces a general matching procedure using permutation group symmetries to relate quark models to the 1/Nc expansion of QCD.

Findings

Successfully matches baryon mass operators to quark model variants.

Provides a symmetry-based framework applicable to various quark interactions.

Enhances understanding of baryon structure in large Nc QCD.

Abstract

We show how to match quark models to the 1/Nc expansion of QCD. As an example we discuss in detail the mass operator of orbitally excited baryons and match it to the one-gluon exchange and the one-boson exchange variants of the quark model. The matching procedure is very general and makes use of the transformation properties of states and operators under S_N^{orb} \times S_N^{sp-fl}, the permutation group acting on the orbital and spin-flavor degrees of freedom of N quarks.