Semileptonic decays of pseudoscalar mesons to the scalar f0 meson

The transition form factors of Ds→f0ℓν, D→f0ℓν and Bu→f0ℓν decays are calculated within the 3-point QCD sum rule method, assuming that f0 is a quark-antiquark state with a mixture of strange and light quarks. Having obtained the expressions of the transition form factors, the branching ratios of these decays are calculated. The experimental measurement of the branching ratios of these decays can provide a direct estimation of the mixing angle.