Branching Ratio for Alternative Modes of Decay of Hyperons andθ0Mesons

We study those restrictions upon the branching ratios of different decay modes of ${\Sigma }^{+}$, ${\Lambda }^0$, and ${\theta }^0$ imposed by the invariant property of a system composed of nucleons, pions, hyperons, and heavy mesons under the Wigner time reversal. These restrictions give, in fact, upper and lower limits on the various branching ratios. Later, we use a more or less specific model of hyperons and $\theta$ mesons in order to get other possible restrictions on the branching ratios. These results are model-dependent, and subsequently provide a possible test of the model we have chosen.