Weak productions of new charmonium in semi-leptonic decays of B_c

Understand

We study the weak productions of novel heavy mesons, such as $\eta_c^{\prime}$, $h_c$, $h_c^{\prime}$, $\chi_{c0}^{\prime}$, X(3940), Y(3940), X(3872), and Y(4260), in the semi-leptonic $B_c$ decays.

• Since there is still no definite answer for the components of X(3940), Y(3940), X(3872), Y(4260) so far, we will assign them as excited charmonium states with the possible quantum numbers constrained by the current experiments.
• As for the weak transition form factors, we calculate them in the framework of light-cone QCD sum rules approach, which is proved to be a powerful tool to deal with the non-perturbative hadronic matrix element.
• Our results indicate that different interpretations of X(3940) can result in remarkable discrepancy of the production rate in the $B_c$ decays, which would help to clarify the inner structure of the X(3940) with the forthcoming LHC-b experiments.