Spectrum and Bethe-Salpeter amplitudes of Ω baryons from lattice QCD

The Ω baryons with J^P = 3/2^±, 1/2^± are studied on the lattice in the quenched approximation. Their mass levels are ordered as M_3/2⁺ < M_3/2^- ≈ M_1/2^- < _M1/2⁺, as is expected from the constituent quark model. The mass values are also close to those of the four Ω states observed in experiments. We calculate the Bethe-Salpeter amplitudes of Ω(3/2⁺) and Ω(1/2⁺) and find there is a radial node for the Ω(1/2⁺) Bethe-Salpeter amplitude, which may imply that Ω(1/2⁺) is an orbital excitation of Ω baryons as a member of the(D, L_N^P) = (70, 0₂⁺) supermultiplet in the SU(6)⊗O(3) quark model description. Our results are helpful for identifying the quantum numbers of experimentally observed Ω states. (authors)