Possible pentaquarks with heavy quarks

Inspired by the discovery of two pentaquarks $P_{c}(4380)$ and $P_{c}(4450)$ at the LHCb detector, we study possible hidden-charm molecular pentaquarks in the framework of quark delocalization color screening model. Our results suggest that both $N\eta_{c}$ with $IJ^{P}=\frac{1}{2}\frac{1}{2}^{-}$ and $NJ/\psi$ with $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$ are bounded by channels coupling. However, $NJ/\psi$ with $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$ may be a resonance state in the $D-$wave $N\eta_{c}$ scattering process. Moreover, $P_{c}(4380)$ can be explained as the molecular pentaquark of $\Sigma^{*}_{c}D$ with quantum numbers $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$. The state $\Sigma^{*}_{c}D^{*}$ with $IJ^{P}=\frac{1}{2}\frac{5}{2}^{-}$ is a resonance, it may not be a good candidate of the observed $P_{c}(4450)$ because of the opposite parity of the state to $P_{c}(4380)$, although the mass of the state is not far from the experimental value. In addition, the calculation is extended to the hidden-bottom pentaquarks, the similar properties as that of hidden-charm pentaquarks system are obtained.