Three-Pion Decay Modes of Eta andKMesons and a Possible New Resonance

A model which postulates a spin-zero $T=0\mathrm{}$ dipion, proposed earlier to explain an apparent enhancement of the three-pion decay mode of the $\eta$ meson, is applied to obtain detailed predictions concerning the three-pion decays of the $\eta$ and $K$ mesons. Good agreement is found with all the available data on $\eta$ and $K$ spectra and branching ratios if the dipion mass and full width are taken as about 400 MeV and 75 to 100 MeV, respectively, thus providing positive evidence for the existence of a two-pion resonance reported by Samios.