Heavy exotic molecules with charm and bottom

We revisit the formation of pion-mediated heavy-light exotic molecules with both charm and bottom and their chiral partners under the general strictures of both heavy-quark and chiral symmetry. The chiral exotic partners with good parity formed using the (0⁺,1⁺) multiplet are about twice more bound than their primary exotic partners formed using the (0⁻,1⁻) multiplet. The chiral couplings across the multiplets (0^±,1^±) cause the chiral exotic partners to unbind, and the primary exotic molecules to be about twice more bound, for J≤1. Our multi-channel coupling results show that only the charm isosinglet exotic molecules with J^PC=1⁺⁺ bind, which we identify as the reported neutral X(3872). Also, the bottom isotriplet exotic with J^PC=1⁺⁻ binds, which we identify as a mixture of the reported charged exotics Z_b ⁺(10610) and Z_b ⁺(10650). The bound isosinglet with J^PC=1⁺⁺ is suggested as a possible neutral X_b(10532) not yet reported.