Radiative vertex VPγ and η-η′ mixing in light-cone sum rules

In this work, we calculate radiative vertex VPγ (V=ϕ,ω,ρ and P=η,η′) by utilizing ω-ϕ mixing scheme and taking into account the contributions of the three-particle twist-4 distribution amplitudes of the photon in QCD sum rules on light cone. According to experimental data of V→Pγ and P→Vγ from PDG, a value of the η-η′ mixing angle, φ=(40.9±0.5)°, is extracted in the framework of the quark-flavor basis to describe the η-η′ system.