Systematic analysis of the form factors of Bc→ηc, J/ψ and corresponding weak decays

The form factors of Bc meson decaying to charmonium ηc and J/ψ are analyzed in the framework of three-point QCD sum rules. In these analyses, the contributions of the vacuum condensate terms gₛ²G² and f³G³ are considered. In addition, the decay widths and branch ratios of several decay channels are obtained by using the calculated form factors. These decay processes include the nonleptonic decay processes of Bc⁻ → ηc π⁻, ηc K⁻, ηc ρ⁻, ηc K*-, Bc⁻ → J/ψ π⁻, J/ψ K⁻, J/ψ ρ⁻, J/ψ K*-, and the semileptonic decay channels of Bc⁻ → ηc l ν̄, Bc⁻ → J/ψ l ν̄. These results about the form factors and decay properties of Bc meson provide useful information to us to study the heavy-quark dynamics and find new physics(NP) beyond Standard Model(SM).