Understanding the newly observed $\Omega_c$ states through their decays

Abstract

The strong and radiative decay properties of the low-lying $\Omega_c$ states are studied in a constituent quark model. We find that the newly observed $\Omega_c$ states by the LHCb Collaboration can fit in well the decay patterns. Thus, their spin-parity can be possibly assigned as the following: (i) The $\Omega_c(3000)$ has $J^P=1/2^-$ and corresponds to the narrow $1P$ mixed state $|1^2P_{\lambda}\frac{1}{2}^-\rangle_1$, its partner $|1^2P_{\lambda}\frac{1}{2}^-\rangle_2$ should be a broad state with a width of $\sim 100$ MeV. (ii) The $\Omega_c(3050)$ and $\Omega_c(3066)$ can be assigned to be two $J^P=3/2^-$ states, $|1^4P_{\lambda}\frac{3}{2}^-\rangle$ and $|1^2P_{\lambda}\frac{3}{2}^-\rangle$, respectively. (iii) The $\Omega_c(3090)$ can be assigned as the $|1^4P_{\lambda}\frac{5}{2}^-\rangle$ state with $J^P=5/2^-$. (iv) The $\Omega_c(3119)$ might correspond to one of the two $2S$ states of the first radial excitations, i.e. $|2^2S_{\lambda\lambda}\frac{1}{2}^+\rangle$ or $|2^4S_{\lambda\lambda}\frac{3}{2}^+\rangle$.