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 ${\Xi }_c(2882{)}^0$, which completes a sequence of four narrow ${\Xi }_c$ structures together with the ${\Xi }_c(2923{)}^0$, ${\Xi }_c(2939{)}^0$, and ${\Xi }_c(2965{)}^0$. Their characteristic mass-splitting pattern closely parallels that of the ${\Omega }_c(3000{)}^0$, ${\Omega }_c(3050{)}^0$, ${\Omega }_c(3066{)}^0$, and ${\Omega }_c(3090{)}^0$ states, providing strong constraints on their spectroscopic assignments. We classify the seven $P$-wave states in each of the ${\Sigma }_Q$, ${\Xi }_Q^{\prime }$, and ${\Omega }_Q$ 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 ${\Xi }_c$ and the four lowest narrow ${\Omega }_c$ structures in terms of the corresponding $\lambda$-mode excitations. Extending the same framework to the bottom sector, we obtain a coherent picture of the observed ${\Sigma }_b$, ${\Xi }_b$, and ${\Omega }_b$ structures. In particular, the ${\Sigma }_b(6097)$, ${\Xi }_b(6227)$, and ${\Omega }_b(6350)$ structures may each contain an unresolved pair of nearby $P$-wave states. We also predict two additional ${\Sigma }_b$ states, two additional ${\Xi }_b^{\prime }$ states, and one additional ${\Omega }_b$ state, all of which are expected to be relatively narrow and remain to be identified experimentally.

Comments: 19 pages, 1 figure, 3 tables, suggestions and comments are welcome