Exclusive production of the X(3872) in B meson decay -: art. no. 074005

If the recently discovered charmoniumlike state X(3872) is a loosely bound S-wave molecule of the charm mesons D-0(D) over bar*(0) or D*(0)(D) over bar (0), it can be produced through the weak decay of the B meson into D-0(D) over bar*K-0 or D*(0)(D) over bar K-0 followed by the coalescence of the charm mesons at a long-distance scale set by the scattering length of the charm mesons. The long-distance factors in the amplitude for the decay B -> XK are determined by the binding energy of X, while the short-distance factors are essentially determined by the amplitudes for B -> D-0(D) over bar*K-0 and B -> D*(0)(D) over bar K-0 near the thresholds for the charm mesons. We obtain a crude determination of the short-distance amplitudes by analyzing data from the BABAR Collaboration on the branching fractions for B ->(D) over bar (DK)-D-(*)-K-(*) using a factorization assumption, heavy-quark symmetry, and isospin symmetry. The resulting order-of-magnitude estimate of the branching fraction for B+-> XK+ is compatible with observations provided that J/psi pi(+)pi(-) is a major decay mode of the X. The branching fraction for B-0-> XK0 is predicted to be suppressed by more than an order of magnitude compared to that for B+-> XK+.