Heavy quark spin selection rule and the properties of the X(3872)

Abstract

The properties of the resonance X(3872) are discussed under the assumption that this resonance is dominantly a `molecular' $J^{PC}=1^{++}$ state of neutral $D$ and $D^*$ mesons. It is argued that in these properties should dominate the states with the total spin of the charmed quark-antiquark pair equal to one. As a practical application of this observation the ratio of the rates of the decays $X \to π^0 χ_{cJ}$ for different $J$ is predicted. It is also pointed out that the total rate of these decays is likely to be comparable to that of the observed transitions $X \to π^+ π^- Jψ$ and $X \to π^+ π^- π^0 Jψ$. The decays of the X into light hadrons and its production in hadronic processes are also briefly discussed.