Bc → Bs J form factors and Bc decays into Bs J in covariant light-front approach

We suggest to study the and its excitations in the decays. We calculate the and form factors within the covariant light-front quark model, where the and denote an s-wave or p-wave and meson, respectively. The form factors at are directly computed while their -distributions are obtained by extrapolation. The derived form factors are then used to study semileptonic decays, and nonleptonic . Branching fractions and polarizations are predicted in the standard model. We find that the branching fractions are sizable and might be accessible at the LHC experiment and future high-energy colliders with a high luminosity at the Z-pole. The future experimental measurements are helpful to study the nonperturbative QCD dynamics in the presence of a heavy spectator and also of great value for the study of spectroscopy.