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Measurement of Rare Kaon Decay K^+ -> PI^+NUNU-BAR

Shaomin Chen
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Abstract

A decade long search for the rare kaon decay to pi^+nunu-bar has been pursued by E787. Two signal events are observed, giving a measurement of the branching ratio Br(K^+ -> PI^+NUNU-BAR)=1.57^+1.75_-0.82 x 10^-10 and a constraint on the Cabibbo-Kobayashi-Maskawa (CKM) matrix element 0.007<|Vtd|<0.030 (68% C.L.).

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Shaomin Chen. 2002-05-13. Measurement of Rare Kaon Decay K^+ -> PI^+NUNU-BAR. https://arxiv.org/abs/hep-ex/0205031

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