THE Z → c (c)over bar → γγ*, Z → b(b)over bar → γγ* TRIANGLE DIAGRAMS AND THE Z → γψ, Z → γγ DECAYS

We expounded an approach for studying the Z -> gamma psi and Z -> gamma gamma decay based on the sum rules for the Z -> c (c)over bar -> gamma gamma*, Z -> b(b)over bar -> gamma gamma* amplitudes and their derivatives. We calculate the branching ratios of the Z -> gamma psi and Z -> gamma gamma decays under different suppositions about the saturation of the sum rules. We find the lower bounds of I pound (psi) BR(Z -> gamma psi) = 1.95 center dot 10 (-7) and I pound (gamma) BR(Z -> gamma gamma) = 7.23 center dot 10(-7) and discuss deviations from the lower bounds including the possibility of BR[Z -> gamma J/psi(1S)] similar to BR[Z -> gamma gamma(1S)] similar to 10 (-6) , which is probably measurable at the LHC. Moreover, we calculate the angle distributions in the Z -> gamma psi and Z -> gamma gamma decays.