CP violation in B decays at Belle

4th Symposium on Prospects in the Physics of Discrete Symmetries

Santelj, L.^1

High Energy Accelerator Research Organization (KEK), Tsukuba, Japan^1

关键词: Asymmetric energy;    Belle detectors;    Branching fractions;    CP violations;    CP-violation parameters;    Data sample;    Measurements of;    Time dependent;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/631/1/012037/pdf
DOI  :  10.1088/1742-6596/631/1/012037

来源: IOP

【 摘 要 】

Using the full data sample collected with the Belle detector at the KEKB asymmetric-energy e+e-collider, we present three recent measurements of time-dependent CP violation in B decays that are sensitive to potential new physics contributions and a measurement of branching fraction of the B0→ π0π0decay. We studied B → ωK decays and measured the values of CP violation parameters in B0→ ωK0Sto be AωK0S= 0.36 ± 0.19 ± 0.05 and SωK0S= +0.91 ± 0.32 ± 0.05, which gives the first evidence of CP violation in this decay. From the measurement of CP violation parameters in the B0→ η'K0decay we obtain Sη'K0= 0.68 ± 0.07 ± 0.03 and Aη'K0= +0.03 ± 0.05 ± 0.04, which are the world's most precise values to date. We present the Belle first measurement of CP violation parameters in B0→ K0Sηγ decay, where we measure SK0Sηγ= -1.32 ± 0.77 ± 0.36 and AK0Sηγ= -0.48 ± 0.41 ± 0.07 (preliminary). Finally we present our preliminary measurement of the B0→ π0π0branching fraction. We measure B(B0→ π0π0) = (0.89 ± 0.12 ± 0.10) × 10-6, with significantly improved sensitivity compared to previously available results.