Decays of J/ψ and ψ' into vector and pseudoscalar mesons and the pseudoscalar glueball-q(q)over-bar mixing

We introduce a parametrization scheme for J/psi(psi')-> VP where the effects of SU( 3) flavor symmetry breaking and doubly OZI- rule violation ( DOZI) can be parametrized by certain parameters with explicit physical interpretations. This scheme can be used to clarify the glueball - q (q) over bar mixing within the pseudoscalar mesons. We also include the contributions from the electromagnetic ( EM) decays of J/psi and psi' via J/psi(psi')-> gamma* -> VP. Via study of the isospin violated channels, such as J/psi(psi')->rho eta,rho eta', omega pi degrees and phi pi degrees, reasonable constraints on the EM decay contributions are obtained. With up- to- date experimental data for J/psi(psi')-> VP, J/psi(psi')->gamma P and P ->gamma gamma, etc, we arrive at a consistent description of the mentioned processes with a minimal set of parameters. As a consequence, we find that there exists an overall suppression of the psi' -> 3g form factors, which sheds some light on the long- standing 'rho pi puzzle'. By determining the glueball components inside the pseudoscalar eta and eta' in three different glueball - q (q) over bar mixing schemes, we deduce that the lowest pseudoscalar glueball, if it exists, has a rather small q (q) over bar component, and it makes eta( 1405) a preferable candidate for a 0(-+) glueball.