Understanding the low-lying $\hat{I}{\text{c◯}}_c$ structures from a coupled-channel perspective

Abstract

We perform a systematic analysis of the low-lying $\hat{I}{\text{c◯}}_c$ structures in a coupled-channel approach. The couplings between meson-baryon channels, $\hat{I}{ž}_c\bar{K}$, $\hat{I}{ž}_c^{\prime }\bar{K}$, $\hat{I}{ž}_c^{\ast }\bar{K}$, $\hat{I}{\text{c◯}}_c\hat{I}\cdot$ and $\hat{I}{\text{c◯}}_c^{\ast }\hat{I}\cdot$, and three-quark bare states $\hat{I}{\text{c◯}}_c(1P_{\hat{I}}»)$ are considered. We predict a bound state $\hat{I}{\text{c◯}}_c(2954)$ below the $\hat{I}{ž}_c\bar{K}$ threshold with $(J^P,j)=(1/2^{-},0)$, which can be studied in the final states of $\hat{I}{\text{c◯}}_c^{(\ast )}\ddot{I}€$ and $\hat{I}{\text{c◯}}_c^{(\ast )}{\hat{I}}^3$. Also, the resonances $\hat{I}{\text{c◯}}_c(3000)$ and $\hat{I}{\text{c◯}}_c(3050)$ can be classified as the lower $(J^P,j)=(1/2^{-},1)$ and $(J^P,j)=(3/2^{-},1)$ states, respectively. Our present assignments based on this coupled-channel perspective are significantly different from those of traditional three-quark picture and of molecular scenario. The future BelleII and LHCb experiments can search for the bound state $\hat{I}{\text{c◯}}_c(2954)$ and measure the spin-parities of particles $\hat{I}{\text{c◯}}_c(3000)$ and $\hat{I}{\text{c◯}}_c(3050)$ to test our predictions.

11 pages, 5 figures. Minor modifications, accepted version