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arXiv · hep-ex/0305035

Measurement of the ratio Gamma(K_L -> gamma gamma)/Gamma(K_L -> pi^0 pi^0 pi^0) with the KLOE detector

The KLOE Collaboration
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Abstract

We have measured the ratio R=Gamma(K_L -> gamma gamma)/ Γ(K_L -> 3 pi^0) using the KLOE detector. From a sample of ~ 10^9 phi-mesons produced at DAFNE, the Frascati phi-factory, we select ~ 1.6 10^8 K_L-mesons tagged by observing K_S -> pi^+ pi^- following the reaction e^+ e^- -> phi -> K_L K_S. From this sample we select 27,375 K_L -> gamma gamma events and obtain R = (2.79 \pm 0.02_{stat} \pm 0.02_{syst}) \times 10^{-3}. Using the world average value for BR(K_{L} -> 3 pi^0), we obtain BR(K_{L} -> gamma gamma) = (5.89 \pm 0.07 \pm 0.08) \times 10^{-4} where the second error is due to the uncertainty on the 3 pi^0 branching fraction.

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The KLOE Collaboration. 2003-05-15. Measurement of the ratio Gamma(K_L -> gamma gamma)/Gamma(K_L -> pi^0 pi^0 pi^0) with the KLOE detector. https://doi.org/10.1016/s0370-2693(03)00810-4

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