CInvariance and the (π0e−e+) and (π02γ) Modes of theη-Decay Process

Abstract

The transition probability of the electromagnetic decay process ${\eta }^0\to {\pi }^0+e^{-}+e^{+}$ is calculated in terms of both the angle and the energy difference between the electron-positron pair. It is found that the latter distribution is very sensitive to whether or not $C$ invariance holds in the electromagnetic interaction of hadrons. A similar calculation is done also for the process ${\eta }^0\to {\pi }^0+2\mathrm{}\gamma$. The branching ratio between these two processes is also estimated and the results are discussed.