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Updated: Jun 14, 2025

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Measurements of the Branching Fraction, Polarization, and CP Asymmetry for the Decay B^{0}→ωω
Abstract:
We present a comprehensive study of B^{0}→ωω decays using 772×10^{6} BB[over ¯] pairs collected with the Belle detector at the KEKB e^{+}e^{-} collider. This process is a suppressed charmless decay into two vector mesons and can exhibit interesting polarization and CP violation. The decay is observed for the first time with a significance of 7.9 standard deviations. We measure a branching fraction B=(1.53±0.29±0.17)×10^{-6}, a fraction of longitudinal polarization f_{L}=0.87±0.13±0.13, and a time-integrated CP asymmetry A_{CP}=-0.44±0.43±0.11, where the first uncertainties listed are statistical and the second are systematic. This is the first observation of B^{0}→ωω and the first measurements of f_{L} and A_{CP} for this decay.
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