Understanding the newly observed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msubsup><mml:mi mathvariant="normal">Ξ</mml:mi><mml:mi>c</mml:mi><mml:mn>0</mml:mn></mml:msubsup></mml:math> states through their decays

Abstract

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

Topics & Concepts