Study of the mass spectra of doubly heavy Ξ _QQ and Ω _QQ baryons

LHCb Collaboration first observed a doubly charmed baryon Ξ ⁺⁺cc Ξ cc + + in the Λ ⁺cK⁻π ⁺π ⁺ Λ c + K - π + π + decay with a mass of 3621.40± 0.72± 0.27 3621.40 ± 0.72 ± 0.27 MeV. In this paper, we enumerated the mass spectra of the radial and orbital excited states for the doubly heavy Ξ _QQ Ξ Q Q ′ and Ω _QQ Ω Q Q ′ baryons using the Regge trajectory model and the scaling rules. Our studies suggest that Ξ ⁺⁺cc Ξ cc + + can be grouped into the 1 S -wave state with the spin-parity quantum number JP = 1/2⁺ J P = 1 / 2 + . On the other hand, the mass of Ξ cc Ξ cc state with JP = 3/2⁺ J P = 3 / 2 + is predicted to be 3699.69 ± 4.59 3699.69 ± 4.59 MeV. We also predict the mass spectra of the unknown ground and excited states for the doubly heavy Ξ _QQ Ξ Q Q ′ and Ω _QQ Ω Q Q ′ baryons, which provide useful references for the experimental test in the future.