ND and NB systems in quark delocalization color screening model

The ND and NB systems with I = 0 and 1, J(P) = 1/2(+/-), 3/2(+/-), and 5/2(+/-) are investigated within the framework of the quark delocalization color screening model. The results show that all the positive-parity states are unbound. By coupling to the ND* channel, the state ND with I = 0, J(P) = 1/2(-) can form a bound state, which can be invoked to explain the observed S(2800) state. The mass of the ND* with I = 0, J(P) = 3/2(-) is close to that of the reported Lambda(c)(2940)(+), which indicates that Lambda(c)(2940)(+) can be explained as a ND* molecular state in QDCSM. Besides, the Delta D* with I = 1, J(P) = 5/2(-) is also a possible resonance state. The results of the bottom case of the NB system are similar to those of the ND system. Searching for these states will be a challenging subject of experiments.