Decay of the NeutralπMeson

The possibilities of detecting the parity of the ${\pi }^0$ meson by electromagnetic experiments involving the decay $\gamma$ rays are discussed. It is shown that no experiment can be performed which distinguishes scalar and pseudoscalar decays unless azimuthal angular correlations are measured, assuming that the ${\pi }^0$ decays at rest. As an example, the total coincidence Compton scattering cross section from polarized electron targets is calculated explicitly and shown to be identical for the scalar, pseudoscalar, and parity-nonconserving decay.