Model-Independent Study on M1 transitions in Heavy Quarkonium

Some new results on magnetic dipole (M1) transitions in heavy quarkonium from nonrelativistic effective field theories of QCD are briefly reported. This model-independent approach not only facilitates a systematic and lucid way to investigate relativistic corrections, it also clarifies some inconsistent treatment in previous potential model approach. The impact of our formalism on J/ψ→ηcγ is discussed.