Rare Decay Modes of theηMeson

The rare decay modes of the $\eta$ meson are considered. Since in these decays the electromagnetic interaction for the leptons is well known, this work is concentrated on the strong interactions acting at the $\eta \gamma \gamma$ vertex. A model for the form factor of this vertex function is constructed. In this model the low-energy and the high-energy behavior of the form factor are separately considered. The Bjorken limit is applied to determined the asymptotic behavior of the form factor. Predictions on the branching ratios of both the Dalitz pair and the direct decay modes are given as functions of the various parameters involved. Further experiments are needed to determine these parameters. A discussion of the model is also presented.