  The radiative $\phi\to\pi^0\eta\gamma$ decay is discussed emphasizing the
effects of the $a_0$(980) scalar resonance which dominates the high values of
the $\pi^0\eta$ invariant mass spectrum. In its lowest part, the proposed
amplitude coincides with the reliable and ChPT-inspired contribution coming
from chiral loops. The $a_0$(980) resonance is then incorporated exploiting the
complementarity between ChPT and the linear sigma model for this channel. The
recently reported experimental invariant mass distribution and branching ratio
can be satisfactorily accommodated in our framework. For the latter, a value of
$B(\phi\to\pi^0\eta\gamma)$ in the range $(0.75$--$0.95)\times 10^{-4}$ is
predicted.

High Energy Physics - Phenomenology;High Energy Physics - Experiment