X0 (2866) as a D∗ K ¯ ∗ molecular state X0 (2866) AS A D∗ K ¯ ∗ ... LIU MING-ZHU, XIE JU-JUN, and GENG LI-SHENG

Very recently the LHCb Collaboration reported the discovery of two open charm tetraquark states, X0(2866) and X1(2904). In the present work, we study the D(∗) and K̄(∗) interaction in the one-boson exchange model and show that X0(2866) can be understood as a D∗K̄∗ molecule with I(JP)=0(0+), or at least it has a large molecular component. On the other hand, X1(2904) can not be interpreted as a molecular state. Inspired by the discovery of X0(2866) and the fact that the D∗K̄∗ interaction is strong enough to generate a bound state, we also discuss the likely existence of other open charm molecules. In the meson-meson sector, two molecules near the mass thresholds of DD∗ and D∗D∗ with I(JP)=0(1+) are obtained, and using the heavy quark flavor symmetry their B¯B¯∗ and B¯∗B¯∗ counterparts are also predicted. In the meson-baryon sector, seven open charm molecules with I=1/2 near the mass thresholds of D(∗)ςc(∗) naturally appear, as dictated by the heavy quark spin symmetry.