Understanding the newly observed ${\Xi }_c^0$ states through their decays

Abstract

Inspired by the newly observed ${\Xi }_c^0$ states by the LHCb Collaboration, we investigate the OZI-allowed two-body strong decays of the $\lambda$-mode $1P$ wave ${\Xi }_c^{\prime }$ states within the chiral quark model. Our results indicate that: (i) the newly observed states ${\Xi }_c(2923{)}^0$ and ${\Xi }_c(2939{)}^0$ are good candidates of the $\lambda$-mode $1P$ wave ${\Xi }_c^{\prime }$ states with the spin-parity $J^P=3/2^{-}$, namely ${|}^4{P}_{\lambda }3/2^{-}⟩$ and ${|}^2{P}_{\lambda }3/2^{-}⟩$, respectively. (ii) The another newly observed state ${\Xi }_c(2965{)}^0$ mostly corresponds to the $\lambda$-mode $1P$-wave ${\Xi }_c^{\prime }$ state with the spin-parity $J^P=5/2^{-}$, namely ${|}^4{P}_{\lambda }5/2^{-}⟩$. (iii) For the two $\lambda$-mode $J^P=1/2^{-}$ mixed states, the $|P_{\lambda }1/2^{-}{⟩}_1$ is a narrow state with a width of $\Gamma \sim 15$ MeV and mainly decays into ${\Xi }_c^{\prime }\pi$; while the $|P_{\lambda }1/2^{-}{⟩}_2$ state has a width of $\Gamma \sim 52$ MeV and dominantly decays into ${\Xi }_c\pi$ and ${\Lambda }_{c}K$ channels. If the broad structure around $2880$ MeV observed at LHCb arises from the new ${\Xi }_c^0$ state, this state is very likely to be the $|P_{\lambda }1/2^{-}{⟩}_2$ state.

Comments: 7 pages,2 figures