LARGE-Nc BARYONS

A spin-flavor symmetry emerges for baryons in the large-Nc limit. Large-Nc baryons form irreducible representations of the spin-flavor algebra, and their static properties can be computed in a systematic expansion in 1/Nc. Symmetry relations for static baryon matrix elements are obtained at various orders in the 1/Nc expansion by neglecting subleading 1/Nc corrections. Equivalent relations arise in the quark and Skyrme models, which satisfy the same large-Nc group theory as quantum chromodynamics (QCD). The 1/Nc expansion yields useful results for QCD baryons with Nc = 3.