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 of authors suggest that they are not the conventional $cbar s$ quark model states, but possibly are four-quark states, molecule states or mixtures of a P-wave $cbar s$ and a four-quark state. In this work, we follow the four-quark-state picture, and study the masses of $cnbar nbar s/csbar sbar s$ 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 ($cnbar nbar s/csbar sbar s$) 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.
Download