Doubly Charmed Pentaquarks

Abstract

The LHCb Collaboration, using its full data set from runs $1$ and $2$, announced in $2019$ a surprising update of the hidden-charm pentaquark states $P_c(4380{)}^{+}$ and $P_c(4450{)}^{+}$, observed in 2015. A new state, $P_c(4312{)}^{+}$, was clearly seen at lower energies; furthermore, the original $P_c(4450)$ resonance was resolved into two individual states, named the $P_c(4440{)}^{+}$ and the $P_c(4457{)}^{+}$. Motivated by the fact that these new hidden-charm pentaquark states were successfully predicted by our chiral quark model, we extend herein such study to the doubly charmed sector. The analyzed total spin and parity quantum numbers are $J^P={\frac{1}{2}}^{-}$, ${\frac{3}{2}}^{-}$ and ${\frac{5}{2}}^{-}$, in the $I=\frac{1}{2}$ and $\frac{3}{2}$ isospin channels. We find several possible narrow baryon-meson resonances (theoretical masses in parenthesis): $I{J}^P=\frac{1}{2}{\frac{1}{2}}^{-}$ ${\Sigma }_{c}D(4356)$, $\frac{1}{2}{\frac{3}{2}}^{-}$ ${\Sigma }_c^{\ast }D(4449)$, $\frac{3}{2}{\frac{1}{2}}^{-}$ ${\Sigma }_{c}D(4431)$, $\frac{3}{2}{\frac{1}{2}}^{-}$ ${\Sigma }_{c}D(4446)$, $\frac{3}{2}{\frac{3}{2}}^{-}$ ${\Sigma }_c{D}^{\ast }(4514)$ and $\frac{3}{2}{\frac{5}{2}}^{-}$ ${\Xi }_{cc}^{\ast }\rho (4461)$ whose widths are $4.8$, $8.0$, $2.6$, $2.2$, $4.0$ and $3.0\text{MeV}$, respectively. Moreover, one shallow bound-state is found, too, with quantum numbers $I{J}^P=\frac{1}{2}{\frac{3}{2}}^{-}$ ${\Xi }_{cc}^{\ast }\pi (3757)$. These doubly charmed pentaquark states are expected to be identified in future experiments.

Comments: 15 pages, 14 Tables, 11 Figures. arXiv admin note: text overlap with arXiv:1809.06193