A consistent description of ρ0 → ππγ decays including σ(500) meson effects -: art. no. 048

A consistent description of sigma(500) meson effects in rho(0) --> pi(0)pi(0)gamma and pi(+)pi(-)gamma decays is proposed in terms of reasonably simple amplitudes which reproduce the expected chiral-loop behaviour for large m(sigma) values. For the neutral case, in addition to the well known omega exchange, there is an important contribution from the sigma(500) meson that is in agreement with recent experimental data. For the charged case, where the dominant contribution comes from bremsstrahlung, the effects of the sigma(500) meson are relevant only at high values of the photon energy and compatible with present data. A combined analysis of both processes with moderately improved experimental information should contribute decisively to clarify the status of this controversial sigma(500) meson.