Unified spectroscopy of $P$-wave flavor-sextet heavy baryons from QCD sum rules

Abstract

We investigate the $P$-wave flavor-sextet charmed and bottom baryons within heavy quark effective theory. A key motivation is provided by the recent evidence for the $Ξ_c(2882)^0$, which completes a sequence of four narrow $Ξ_c$ structures together with the $Ξ_c(2923)^0$, $Ξ_c(2939)^0$, and $Ξ_c(2965)^0$. Their characteristic mass-splitting pattern closely parallels that of the $Ω_c(3000)^0$, $Ω_c(3050)^0$, $Ω_c(3066)^0$, and $Ω_c(3090)^0$ states, providing strong constraints on their spectroscopic assignments. We classify the seven $P$-wave states in each of the $Σ_Q$, $Ξ_Q^\prime$, and $Ω_Q$ sectors ($Q=c,b$), calculate their masses and intra-doublet mass splittings using QCD sum rules, and study their strong decays using light-cone sum rules. Configuration mixing between states with the same quantum numbers is also investigated. The combined analysis favors a common interpretation of the four narrow $Ξ_c$ and the four lowest narrow $Ω_c$ structures in terms of the corresponding $λ$-mode excitations. Extending the same framework to the bottom sector, we obtain a coherent picture of the observed $Σ_b$, $Ξ_b$, and $Ω_b$ structures. In particular, the $Σ_b(6097)$, $Ξ_b(6227)$, and $Ω_b(6350)$ structures may each contain an unresolved pair of nearby $P$-wave states. We also predict two additional $Σ_b$ states, two additional $Ξ_b^\prime$ states, and one additional $Ω_b$ state, all of which are expected to be relatively narrow and remain to be identified experimentally.