Relativistic effects in radiative transitions of charmonia

In the framework of a relativistic quark model constructed in an infinite momentum frame, corrections of the order of v/c are obtained in the formulas which express amplitudes of the transitions ψ(ψ′) → η c (η′ c )γ, χ J → ψγ, ψ′ → χ J γ, h c → η c γ, η′ c → h c γ through overlap integrals ∫ φf(q)φi(q)dq, ∫ φf(r)rφi(r)dr. These corrections lead to a considerable suppression of Γ(ψ → η c γ), however, they are insufficient