Reanalysis of the Lowest-Mass Negative-Parity Baryon Resonances Using the Symmetric Quark Model

The lowest-mass negative-parity baryon resonances are reanalyzed using a systematic $\mathrm{SU}\left(6\right)\mathrm{}$ analysis of mass operators developed earlier in the symmetric quark model. Fourteen resonances with known spin and parity are fitted to within 15 MeV on the average, using a six-parameter mass formula. Strong mixings are found for $J^P={\frac{1}{2}}^{-}$ and ${\frac{3}{2}}^{-}$ resonances, and thus the Gell-Mann-Okubo mass formula cannot be expected to hold for these resonances, and there is no sense in trying to group them into octets and decuplets.