Angular distribution functions in the decays of ψ' and ψ'' directly produced in unpolarized p̄p collisions

We calculate the combined angular distribution of the two photons and of the electron in the triple cascade process p̄p→ψ',ψ''→χJ+γ1→(ψγ2) +γ1→(e+e-)+γ2+γ1 (J=0,1,2) when p̄ and p are unpolarized. The answer is given in the ψ',ψ'' restframe or the p̄p c.m. frame. By measuring this angular distribution one can determine the magnitudes as well as the relative phases of the angular momentum helicity amplitudes in the radiative decay processes ψ',ψ''→χJ+γ1 and χJ→ψ+γ2 (J=0,1,2) as well as the relative magnitudes of the angular momentum helicity amplitudes in the processes p̄p→ψ'ψ'' and ψ→e+e-.