Production rates of Ds+ Ds- and D D ¯ molecules in B decays

Motivated by the recent discovery of a charmonium X(3960) in B decays by the LHCb Collaboration, the likely existence of two bound/virtual states (denoted by Xss¯ and Xqq¯) below the Ds+Ds- and D¯D mass thresholds has been reexamined recently. In this work, we employ the effective Lagrangian approach to calculate their production rates in B decays utilizing triangle diagrams. Our results show that the production yields of B+→Xss¯K+ and B+→Xqq¯K+ are of the order of 10-4, in agreement with the relevant experimental data, which indicates that, if the Ds+Ds- and D¯D bound states indeed exist, they can be detected in B decays. Moreover, we calculate the production rate of B+→X(3960)K+ assuming that X(3960) is a resonant state of Ds+Ds- and find that it is also of the order of 10-4 but a bit smaller than that as a Ds+Ds- bound state.