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arXiv · 0707.4336

Search for the CP-violating decays $Υ(4S) B0\bar{B}0 J/K0_S + J/ψ(η_c)K0_S$

O. Tajima·M Hazumi
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Abstract

We report the first search for CP violating decays of the $Υ(4S)$ using a data sample that contains 535 million $Υ(4S)$ mesons with the Belle detector at the KEKB asymmetric-energy e^+ e^- collider. A partial reconstruction technique is employed to enhance the signal sensitivity. No significant signals were observed. We obtain an upper limit of $4 \times 10^{-7}$ at the 90 % confidence level for the branching fractions of the $CP$ violating modes, $Υ(4S) \to B^0\bar{B}^0 \to J/ψK^0_S + J/ψ(η_c) K^0_S$. Extrapolating the result, we find that an observation with 5$σ$ significance is expected with a 30 ab^{-1} data sample, which is within the reach of a future super B factory.

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O. Tajima, M Hazumi. 2007-07-30. Search for the CP-violating decays $Υ(4S) B0\bar{B}0 J/K0_S + J/ψ(η_c)K0_S$. https://doi.org/10.1103/physrevlett.99.211601

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