Improved Measurement of the $K^{+} \to π^{+} ν \bar{ν}$ Branching Ratio

An additional event near the upper kinematic limit for

K^{+} \to π^{+} ν \bar{ν}

has been observed by experiment E949 at Brookhaven National Laboratory. Combining previously reported and new data, the branching ratio is

B (K^{+} \to π^{+} ν \bar{ν}) = ({1.47}_{- 0.89}^{+ 1.30}) \times 10^{- 10}

based on three events observed in the pion momentum region

211 < P < 229 M e V / c

. At the measured central value of the branching ratio, the additional event had a signal-to-background ratio of 0.9.

This publication has 13 references indexed in Scilit:

Further Evidence for the Decay $K^{+} \to π^{+} ν \bar{ν}$
Physical Review Letters, 2002
Further Search for the Decay $K^{+} \to π^{+} ν \bar{ν}$
Physical Review Letters, 2000
Confidence level computation for combining searches with small statistics
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1999
Performance of fine-mesh photomultiplier tubes designed for an undoped-CsI endcap photon detector
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998
Central tracking chamber with inflated cathode-strip foils
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1998
Evidence for the Decay $K^{+} \to π^{+} ν \bar{ν}$
Physical Review Letters, 1997
500 MHz transient digitizers based on GaAs CCDs
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1997
CsI endcap photon detector for a K/sup +//spl rarr//spl pi//sup +//spl nu//spl nu
IEEE Transactions on Nuclear Science, 1995
Waveform digitizing at 500 MHz☆
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1989
Axions and Family Symmetry Breaking
Physical Review Letters, 1982

Improved Measurement of theK+→π+νν¯Branching Ratio