Abstract
Experiment E949 at Brookhaven National Laboratory has observed three new events consistent with the decay K+→π+νν̄ in the pion momentum region 140<Pπ<199MeV/c in an exposure of 1.71×1012 stopped kaons with an estimated total background of 0.93±0.17(stat)-0. 24+0.32(syst) events. This brings the total number of observed K+→π+νν̄ events to seven. Combining this observation with previous results, assuming the pion spectrum predicted by the standard model, results in a branching ratio of B(K+→π+νν̄)=(1.73-1.05+1.15) ×10-10. An interpretation of the results for alternative models of the decay K+→π++nothing is also presented.
Original language | English |
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Article number | 092004 |
Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |
Volume | 79 |
Issue number | 9 |
DOIs | |
Publication status | Published - May 1 2009 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)