Excited Baryons in Large Nc QCD: Matching the 1/Nc expansion to quark models using the permutation group S_N
Abstract
Description
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.
6 pages, Invited plenary talk at NSTAR2007, Workshop on the Physics of Excited Nucleons, 5 - 8 September 2007, Bonn, Germany
6 pages, Invited plenary talk at NSTAR2007, Workshop on the Physics of Excited Nucleons, 5 - 8 September 2007, Bonn, Germany