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 $|1^2{P}_{\lambda }{\frac{1}{2}}^{-}{⟩}_1$, its partner $|1^2{P}_{\lambda }{\frac{1}{2}}^{-}{⟩}_2$ 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, $|1^4{P}_{\lambda }{\frac{3}{2}}^{-}⟩$ and $|1^2{P}_{\lambda }{\frac{3}{2}}^{-}⟩$, respectively. (iii) The ${\Omega }_c(3090)$ can be assigned as the $|1^4{P}_{\lambda }{\frac{5}{2}}^{-}⟩$ 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. $|2^2{S}_{\lambda \lambda }{\frac{1}{2}}^{+}⟩$ or $|2^4{S}_{\lambda \lambda }{\frac{3}{2}}^{+}⟩$.

Comments: 7 pages, 4 figures. To appear in PRD