Interference in the $K\overline{K}$ decay mode of the $f^0$ and $A_2^0$ mesons is discussed in terms of the mass-matrix formalism. It is shown that the measurement of the $f^0\to K\overline{K}$ branching ratio can be in error by an order of magnitude if interference is not properly accounted for. Data from ${\pi }^{+}p$ and ${\pi }^{-}p$ reactions at 18.5 $\frac{\mathrm{GeV}}{c}$ are used to determine the $\frac{(f^0\to K\overline{K})}{(f^0\to \pi \pi )}$ branching ratio $R_{f^0}$ using the known $A_2\to K\overline{K}$ branching ratio and assuming a value for the coherence factor. We find $9\%\le R_{f^0}\le 18\%$.

• Received 2 August 1971

DOI:https://doi.org/10.1103/PhysRevD.5.1564