Interpretation of the newly observed ${\mathrm{\Omega }}_c^0$ resonances

We study the charmed and bottomed doubly strange baryons within the heavy-quark-light-diquark framework. The two strange quarks are assumed to lie in $S$ wave and thus their total spin is 1. We calculate the mass spectra of the $S$- and $P$-wave orbitally excited states and find the ${\mathrm{\Omega }}_c^0(2695)$ and ${\mathrm{\Omega }}_c^0(2770)$ fit well as the $S$-wave states of charmed doubly strange baryons. The five newly ${\mathrm{\Omega }}_c^0(X)$ resonances observed by the LHCb Collaboration, i.e., ${\mathrm{\Omega }}_c^0(3000)$, ${\mathrm{\Omega }}_c^0(3050)$, ${\mathrm{\Omega }}_c^0(3066)$, ${\mathrm{\Omega }}_c^0(3090)$, and ${\mathrm{\Omega }}_c^0(3119)$, can be interpreted as the $P$-wave orbitally excited states. In heavy quark effective theory, we analyze their decays into the ${\mathrm{\Xi }}_c^{+}{K}^{-}$ and ${\mathrm{\Xi }}_c^{\prime +}{K}^{-}$, and point out that decays of the five P-wave ${\mathrm{\Omega }}_c^0$ states into the ${\mathrm{\Xi }}_c^{+}{K}^{-}$ and ${{\mathrm{\Xi }}_c^{\prime }}^{+}{K}^{-}$ are suppressed by either heavy quark symmetry or phase space. The narrowness of the five newly observed ${\mathrm{\Omega }}_c^0(X)$ states can then be naturally interpreted with heavy quark symmetry.