Strong decays of the latest LHCb pentaquark candidates in hadronic molecule pictures

Abstract

We investigate the observed pentaquark candidates $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ from the latest LHCb measurement, as well as four possible spin partners in the ${\bar{D}}^{(\ast )}{\Sigma }_c^{\ast }$ system predicted from the heavy quark spin symmetry with the hadronic molecule scenarios. Similar to the previous calculation on $P_c(4380)$ and $P_c(4450)$, the partial widths of all the allowed decay channels for these $P_c$ states are estimated with the effective Lagrangian method. The cutoff dependence of our numerical results are also presented. Comparing with the experimental widths, our results show that $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ can be described well with the spin-parity-$1/2^{-}$-$\bar{D}{\Sigma }_c$, $1/2^{-}$-${\bar{D}}^{\ast }{\Sigma }_c$ and $3/2^{-}$-${\bar{D}}^{\ast }{\Sigma }_c$ molecule pictures, respectively.

Comments: 13 pages,8 figures