Inelastic and finite width effects on rho-meson propagator and correction to radiative decay of mesons

Inelastic and finite-width effects to the rho-meson propagator are studied in the framework of the Gounaris-Sakurai and Renard approximation of many channel N/D method. For the rho-meson, the finite-width factor is substantially modified by the A1π closed channel essentially due to the large GAMMA sub(rho=2π), the large rhoA1π coupling and the S-wave behaviour of rho → A1π process. By using the recently reported experimental data on the process rho- → π-γ, it is pointed out that the experimental ratios GAMMA sub(ω=πγ)/GAMMA sub(rho=πγ) and GAMMA sub(eta'=rhoγ)/GAMMA sub(eta'=ωγ) are well reproduced by the vector-meson dominance model if we take account of the finite-width factor. (author)