Electric dipole transitions of heavy quarkonium in pNRQCD

We propose a systematic, model-independent treatment of electric dipole transitions of heavy quarkonium. Within an effective field theory, concretely potential non-relativistic QCD, the relativistic corrections of relative order \(v^2\) to the decay rate are derived. An existing formalism developed for M1 decays will be extended for our purpose. We scrutinize and complement former results from potential model calculations.