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 Nη_c with IJ^P = (1)/(2)(1)/(2)^- and NJ/ψ with IJ^P = (1)/(2)(3)/(2)^- are bounded by channels coupling. However, NJ/ψ with IJ^P = (1)/(2)(3)/(2)^- may be a resonance state in the D-wave Nη_c scattering process. Moreover, P_c(4380) can be explained as the molecular pentaquark of Σ^*_cD with quantum numbers IJ^P = (1)/(2)(3)/(2)^-. The state Σ^*_cD^* with IJ^P = (1)/(2)(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, and similar properties to that of hidden-charm pentaquarks system are obtained. (orig.)