Chiral SU(3) quark model study of tetraquark states: Cnn̄s̄/ css̄s̄*

The new members of the charm-strange family D^* _sJ(2317), D_sJ(2460), and D_s(2632), which have the surprising properties, are challenging the present models. Many theoretical interpretations have been devoted to this issue. Most authors suggest that they are not the conventional c quark model states, but possibly are four-quark states, molecule states, or mixtures of a P-wave c and a four-quark state. In this work, we follow the four-quark-state picture, and study the masses of cn/cs states (n is u or d quark) in the chiral SU(3) quark model. The numerical results show that the mass of the mixed four-quark state (cn/cs) with spin parity J^P = 0⁺ might not be D_s(2632). At the same time, we also conclude that D^*_sJ (2317) and D_sJ (2460) cannot be explained as the pure four-quark state.