New Measurement Of The K+->Pi(+)Nu Nu Branching Ratio

Three events for the decay K+->pi(+)nu have been observed in the pion momentum region below the K+->pi(+)pi(0) peak, 140 < P-pi < 199 MeV/c, with an estimated background of 0.93 +/- 0.17(stat.)(-0.24)(+0.32)(syst.) events. Combining this observation with previously reported results yields a branching ratio of B(K+->pi(+)nu nu)=(1.73(-1.05)(+1.15))x10(-10) consistent with the standard model prediction.