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arXiv · hep-ex/0107068

Search for the decay B^0 --> gamma-gamma

the BABAR Collaboration·B. Aubert
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Abstract

We present a limit on the branching fraction for the decay $B^0 \to γγ$ using data collected at the $Υ(4S)$ resonance with the BABAR detector at the PEP-II asymmetric--energy $e^+e^-$ collider. Based on the observation of one event in the signal region, out of a sample of $21.3 \times 10^6$ $e^+e^- \to Υ(4S) \to B\bar B$ decays, we establish an upper limit on the branching fraction of ${\cal B}(B^0 \to γγ) < 1.7 \times 10^{-6}$ at the 90% confidence level. This result substantially improves upon existing limits.

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the BABAR Collaboration, B. Aubert. 2003-01-28. Search for the decay B^0 --> gamma-gamma. https://doi.org/10.1103/physrevlett.87.241803

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