Semileptonic decays of Bc mesons into charmonium states

In this work we study the semileptonic decays of Bc meson. We evaluated Bc→ D D * , B c → D s D s * and Bc→ηc→ J / ψ transitions form factors in the full kinematical region within the covariant quark model. The calculated form factors are used to evaluate the semileptonic decays of Bc meson and it was defined ratios (Rηc , RJ/ψ, RD ,RD*) of the branching ratios, which will be hopefully tested on LHC experiments.We compare the obtained results with the results from other theoretical approaches