Systematic analysis of the form factors of B → η, J/ψ and corresponding weak decays

The form factors of B c → η c and B c → J / ψ are analyzed in the framework of three-point QCD sum rules. In the calculations, the contributions of the vacuum condensate terms 〈 g s 2 G G 〉 and 〈 g s 3 G G G f 〉 are considered. In addition, the decay widths and branching ratios of several decay channels are predicted by using the calculated form factors. These decay processes include the nonleptonic decays B c − → η c π − , η c K − , η c ρ − , η c K ⁎ − , J / ψ π − , J / ψ K − , J / ψ ρ − , J / ψ K ⁎ − , and the semileptonic decays B c − → η c l ν ¯ , J / ψ l ν ¯ . These results about the form factors and decay properties of B c meson provide useful information for us to study the heavy-quark dynamics and find new physics beyond Standard Model.