Covariant light-front approach for heavy quarkonium: decay constants, P → γγ and V → Pγ

The light-front approach is a relativistic quark model and offers many insights into the internal structures of the hadronic bound states. In this study, we apply the covariant light-front approach to ground-state heavy quarkonium. The pesudoscalar and vector meson decay constants are discussed. We present a detailed study of two-photon annihilation P → γγ and magnetic dipole transition V → Pγ processes. The numerical predictions of the light-front approach are consistent with the experimental data and those in other approaches. The relations of the light-front approach with the other methods are discussed in brief