Measurement of Ke4+ - decay rates and test of the ΔS = ΔQ rule☆

Abstract In a study of 1609 K e4 decays observed at the CERN PS, the rate of K + → π + π − e + ν was found to be (3.32 ± 0.31) × 10 3 sec −1 . An upper limit of 43 sec −1 at the 95 % confidence level was obtained for the ΔS = ΔQ violating mode K + → π + π + e − ν .