Investigations on the weak decays of DB̅ molecules

The decays of exotic states discovered experimentally always proceed via the strong and electromagnetic interactions. Recently, a tetraquark state with the quark content bcq̅q̅ was predicted by Lattice QCD simulations. It is below the mass threshold of DB̅, which can only decay via the weak interaction. In this work, based on the decay mechanism of T_cc as a DD^* molecule, we propose that the decays of the bcq̅q̅ tertaquark state as a DB̅ molecule proceed via the Cabibbo-favored weak decays of the B̅ or D meson, accompanied by the tree-level decay modes and the triangle decay modes. Our results indicate that the branching fraction of the DB̅ molecule decaying into π^+ K^-B̅^0 is sizable, which is a good channel to observe the DB̅ molecule in future experiments.