Analysis of the [56,2+] baryon masses in the 1/Nc expansion

The mass spectrum of the positive parity [56,2+] baryons is studied in the 1/Nc expansion up to and including O(1/Nc) effects with SU(3) symmetry breaking implemented to first order. A total of eighteen mass relations result, several of which are tested with the available data. The breaking of spin-flavor symmetry is dominated by the hyperfine interactions, while spin–orbit effects are found to be small.