Measurement of the branching fraction and \it CP-violating asymmetry of the decay B⁰ → π⁰ π⁰ using 387 million bottom-antibottom meson pairs in Belle II data

2024/12/18 by Belle II Collaboration, Adachi, I., Aggarwal, L. +437
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex)

paper · doi:10.48550/arxiv.2412.14260

Abstract

We measure the branching fraction and \it CP-violating flavor-dependent rate asymmetry of B⁰ → π⁰ π⁰ decays reconstructed using the Belle II detector in an electron-positron collision sample containing 387 × 10⁶ BB pairs. Using an optimized event selection, we find 126± 20 signal decays in a fit to background-discriminating and flavor-sensitive distributions. The resulting branching fraction is (1.25 ± 0.23)× 10^-6 and the \it CP-violating asymmetry is 0.03 ± 0.30.

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