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A search for the decay $B^+ \to K^+ ν\barν$

B. Aubert·BABAR Collaboration
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Abstract

We search for the rare flavor-changing neutral-current decay $B^+ \to K^+ ν\barν$ in a data sample of 82 fb$^{-1}$ collected with the {\sl BABAR} detector at the PEP-II B-factory. Signal events are selected by examining the properties of the system recoiling against either a reconstructed hadronic or semileptonic charged-B decay. Using these two independent samples we obtain a combined limit of ${\mathcal B}(B^+ \to K^+ ν\barν)<5.2 \times 10^{-5}$ at the 90% confidence level. In addition, by selecting for pions rather than kaons, we obtain a limit of ${\mathcal B}(B^+ \to π^+ ν\barν)<1.0 \times 10^{-4}$ using only the hadronic B reconstruction method.

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B. Aubert, BABAR Collaboration. 2004-11-18. A search for the decay $B^+ \to K^+ ν\barν$. https://doi.org/10.1103/physrevlett.94.101801

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