Test of the quantum-theoretical behavior of the K/sup 0/-- anti K/sup 0/ system

The magnitude of the K/sub S/--K/sub L/ interference term in the ..pi../sup +/..pi../sup -/ decay mode of regenerated K/sup 0/'s has been studied. The data at each momentum are consistent with the general expectations of quantum theory and with the conventional phenomenology of CP violation. The ratio of the measured amplitude of the interference to its predicted value is k = 0.95 +- 0.034 from our data alone. When additional data from other experiments are used, k = 0.97 +- 0.02. (AIP)