The strong decays of charm-strange baryons up to $N=2$ shell are studied in a chiral quark model. The theoretical predictions for the well-determined charm-strange baryons, ${\Xi }_c^{*}(2645)$, ${\Xi }_c(2790)$, and ${\Xi }_c(2815)$, are in good agreement with the experimental data. This model is also extended to analyze the strong decays of the other newly observed charm-strange baryons ${\Xi }_c(2930)$, ${\Xi }_c(2980)$, ${\Xi }_c(3055)$, ${\Xi }_c(3080)$, and ${\Xi }_c(3123)$. Our predictions are given as follows: (i) ${\Xi }_c(2930)$ might be the first orbital ($1P$) excitation of ${\Xi }_c^{\prime }$ with $J^P=1/2^{-}$ and favors the $|{\Xi }_c^{\prime }{}^{2}P_{\lambda }1/2^{-}⟩$ or $|{\Xi }_c^{\prime }{}^{4}P_{\lambda }1/2^{-}⟩$ state. (ii) ${\Xi }_c(2980)$ might correspond to two overlapping $1P$ excitations of ${\Xi }_c^{\prime }$. The broader resonance with a mass $m\simeq 2.98\mathrm{GeV}$ observed in the ${\Lambda }_c^{+}\overline{K}\pi$ final state is most likely to be the $|{\Xi }_c^{\prime }{}^{2}P_{\rho }1/2^{-}⟩$ state, while the narrower resonance with a mass $m\simeq 2.97\mathrm{GeV}$ observed in the ${\Xi }_c^{*}(2645)\pi$ channel is most likely to be the $|{\Xi }_c^{\prime }{}^{2}P_{\rho }3/2^{-}⟩$ state. (iii) ${\Xi }_c(3080)$ could be classified as the $|{\Xi }_c{S}_{\rho \rho }1/2^{+}⟩$, i.e., the first radial ($2S$) excitation of ${\Xi }_c$. (iv) ${\Xi }_c(3055)$ is most likely to be the second orbital ($1D$) excitation of ${\Xi }_c$ with $J^P=3/2^{+}$ and favors the $|{\Xi }_c{}^{2}D_{\lambda \lambda }3/2^{+}⟩$ state. (v) ${\Xi }_c(3123)$ might be assigned to the $|{\Xi }_c^{\prime }{}^{4}D_{\lambda \lambda }3/2^{+}⟩$, $|{\Xi }_c^{\prime }{}^{4}D_{\lambda \lambda }5/2^{+}⟩$, or $|{\Xi }_c{}^{2}D_{\rho \rho }5/2^{+}⟩$ state. As a byproduct, we calculate the strong decays of the bottom baryons ${\Sigma }_b^{\pm }$, ${\Sigma }_b^{*\pm }$, and ${\Xi }_b^{*}$, which are in good agreement with the recent observations as well.

• Received 16 May 2012

DOI:https://doi.org/10.1103/PhysRevD.86.034024