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. (C) 2016 The Authors. Published by Elsevier B.V.