Spin-flavor structure of large Nc baryons.

Abstract

The spin-flavor structure of large ${\mathit{N}}_{\mathit{c}}$ baryons is described in the 1/${\mathit{N}}_{\mathit{c}}$ expansion of QCD using quark operators. The complete set of quark operator identities is obtained, and used to derive an operator reduction rule which simplifies the 1/${\mathit{N}}_{\mathit{c}}$ expansion. The operator reduction rule is applied to the axial vector currents, masses, magnetic moments, and hyperon nonleptonic decay amplitudes in the SU(3) limit, to first order in SU(3) breaking, and without assuming SU(3) symmetry. The connection between the Skyrme and quark operator representations is discussed. An explicit formula is given for the quark model operators in terms of the Skyrme model operators to all orders in 1/${\mathit{N}}_{\mathit{c}}$ for the two flavor case.