摘要
The new members of the charm-strange family Dsj^*(2317), Dsj(2460), and Ds(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 cs^- quark model states, but possibly are four-quark states, molecule states, or mixtures of a P-wave cs^- and a four-quark state. In this work, we follow the four-quark-state picture, and study the masses of cnn^-s^-/css^-s^- 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 (cnn^-s^-/css^-s^-) with spin parity j^P : 0^+ might not be Ds (2632). At the same time, we also conclude that Dsj^*(2317) and Dsj(2460) cannot be explained as the pure four-quark state.
基金
National Natural Science Foundation of China under Grant No 10475087