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A consistent description of rho0 -> pi pi gamma decays including sigma(500) meson effects

A. Bramon·R. Escribano
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Abstract

A consistent description of $σ(500)$ meson effects in $ρ^0\toπ^0π^0γ$ and $π^+π^-γ$ decays is proposed in terms of reasonably simple amplitudes which reproduce the expected chiral-loop behaviour for large $m_σ$ values. For the neutral case, in addition to the well known $ω$ exchange, there is an important contribution from the $σ(500)$ meson that is in agreement with recent experimental data. For the charged case, where the dominant contribution comes from bremsstrahlung, the effects of the $σ(500)$ 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 $σ(500)$ meson.

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A. Bramon, R. Escribano. 2004-04-14. A consistent description of rho0 -> pi pi gamma decays including sigma(500) meson effects. https://doi.org/10.1088/1126-6708%2F2004%2F02%2F048

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