Mixing of the low-lying three- and five-quark $Ω$ states with negative parity

Mixing of the low-1/2^{-}$and$3/2^{-}$is investigated, employing an instanton-induced quark-antiquark pair creation model, which precludes transitions between$s^{3}$and$s^{4}\bar{s}$configurations. Models with hyperfine interactions between quarks of three different kinds, namely, one-gluon-exchange, Goldstone-boson-exchange (GBE) and an instanton-induced interaction (INS) are called OGE, GBE and INS models, respectively. Numerical results show that the instanton-induced pair creation causes strong mixing between the three- and five-quark configurations with spin 3/2, and that this mixing decreases the energy of the lowest spin 3/2 states in all three different hyperfine interaction models to$\sim 1750\pm50$MeV. On the other hand, transition couplings between$s^3$and$s^{3}q\bar{q}$states with spin 1/2 caused by instanton-induced$q\bar{q}$creation is very small and the resulting mixing of three- and five-quark configurations in the OGE and INS models is negligible, while the mixing of the spin 1/2 states in GBE model is not, but effects of this mixing on energies of mixed states are also very small. Accordingly, the lowest$Ω$ states with negative parity in all three hyperfine interactions models have spin 3/2.

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