We study the effect of the sigma(600) and a_1(1260) resonances in the rho^0
-> pi^+ pi^- gamma decay, within the meson dominance model. Major effects are
driven by the mass and width parameters of the sigma(600), and the usually
neglected contribution of the a_1(1260), although small by itself, may become
sizable through its interference with pion bremsstrahlung, and the proper
relative sign can favor the central value of the experimental branching ratio.
We present a procedure, using the gauge invariant structure of the resonant
amplitudes, to kinematically enhance the resonant effects in the angular and
energy distribution of the photon. We also elaborate on the coupling constants
involved.Comment: 5 pages, 5 figures, accepted for publication in PR