Deriving the existence of BB̄* bound states from the X(3872) and heavy quark symmetry.

We discuss the possibility and the description of bound states between B and B̄mesons. We argue that the existence of such a bound state can be deduced from (i) the weakly bound X(3872) state, (ii) certain assumptions about the short-range dynamics of the DD̄* system and (iii) heavy quark symmetry. From these assumptions the binding energy of the possible BB̄* bound states is determined, first in a theory containing only contact interactions which serves as a straightforward illustration of the method, and then the effects of including the one-pion exchange potential are discussed. In this latter case three isoscalar states are predicted: a positive and negative C-parity ³S1 - ³D1 state with a binding energy of 20 MeV and 6 MeV below threshold, respectively, and a positive C-parity ³P0 shallow state located almost at the BB̄* threshold. However, large uncertainties are generated as a consequence of the l/mQ corrections from heavy quark symmetry. Finally, the newly discovered isovector Zb(10610) state can be easily accommodated within the present framework by a minor modification of the short-range dynamics. [ABSTRACT FROM AUTHOR]