Measurement of the $K^{+}\to {\pi }^{+}\nu \bar{\nu }$ Branching Ratio

The E949 Collaboration

Experiment E949 at Brookhaven National Laboratory studied the rare decay $K^+\toπ^+ν\barν$andotherprocesseswithanexposureof$1.77\times 10^{12}K^+$'s. The data were anal…