Electromagnetic decay of vector mesons as derived from QCD sum rules

The method of QCD sum rules in the presence of the external electromagnetic field is used to treat the problem of the electromagnetic decay of the various vector mesons, including rho --> pi + gamma, K + gamma, and eta' --> and rho + gamma. The induced condensates obtained previously from the study of baryon magnetic moments are adopted, thereby ensuring the parameter-free nature of the present predictions. Further consistency is reinforced by invoking the various QCD sum rules for the meson masses. The numerical results on the various radiative decays agree very well with the experimental data. (C) 1998 Published by Elsevier Science B.V.