Measurements of J/psi decays into a vector and a pseudoscalar meson

We present measurements of the two-body decays of the J/psi into a vector and a pseudoscalar meson. The data, taken with the Mark III detector at the SLAC e/sup +/e/sup -/ storage ring SPEAR, consist of 5.8 x 10/sup 6/ produced J/psi's. The branching ratios for the J/psi decays into rho..pi.., rhoeta, rhoeta', ..omega pi../sup 0/, ..omega..eta, ..omega..eta', phieta, phieta', and K/sup */K are measured; an upper limit on J/psi..-->..phi..pi../sup 0/ is obtained. Using the measured branching ratios we obtain parameters of a phenomenological model of J/psi decays, indicating that the eta and eta' are consistent with being composed only of light and strange quarks. The model is used to obtain the mixing angle in the pseudoscalar nonet. The ..omega pi../sup 0/ electromagnetic form factor is determined. The upper limit on J/psi..-->..phi..pi../sup 0/ is used to study the contributions from electromagnetic doubly--Okubo-Zweig-Iizuka--suppressed decays of the J/psi. .AE