Predicting the D‾D bound states as the partners of X(3872).

In this work, we investigate the SU(3) flavor symmetry, heavy quark spin symmetry and their breaking effects in the di-meson systems. We prove the existence of the [Formula: see text] , [Formula: see text] , and [Formula: see text] bound states as the consequence of two prerequisites in the SU(3) flavor symmetry and heavy quark spin symmetry. The first prerequisite, the X(3872) as the weakly D‾D/D‾D bound state is supported by its mass and decay branching ratios. The second prerequisite, the existence of the [Formula: see text] bound state is supported by the lattice QCD calculation and the observation of χ(3930) by the LHCb Collaboration. We hope the future experimental analyses can search for these bound states in the B→DD‾h processes (h denotes the light hadrons). The [Formula: see text] bound state is also expected to be reconstructed in the J/ψϕ final state in the B→J/ψϕK decay.