Measurement of $CP$ asymmetries in $B^0 \to K_S^0 K_S^0 K_S^0$ decays at Belle II

Abstract We report a measurement of decay-time dependent charge-parity ($CP$) asymmetries in $B^0 \rightarrow K^0_S K^0_S K^0_S$ decays. We use $387 \times 10^6 B\bar{B}$ pairs collected at the $\Upsilon(4S)$ resonance with the Belle II detector at the SuperKEKB asymmetric-energy electron-positron collider. We reconstruct 220 signal events and extract the $CP$-violating parameters $S$ and $C$ from a fit to the distribution of the decay-time difference between the two $B$ mesons. The resulting confidence region is consistent with previous measurements in $B^0 \rightarrow K^0_S K^0_S K^0_S$ and $B^0 \rightarrow (c\bar{c})K^0$ decays, and with predictions based on the standard model.
Tags
Working group Time Dependent CP Violation
Principal authors @  Koji Hara, Kazutaka Sumisawa, Hikaru Tanigawa, Yutaka Ushiroda
Reference Phys.Rev.D 109, 112020 (2024), DOI: 10.1103/PhysRevD.109.112020
Document BELLE2-PUB-PH-2023-023
Links arXiv:2403.02590, Inspire, PRD
Bibtex 
@article{Belle-II:2024tqu,
    author = "Adachi, I. and others",
    collaboration = "Belle-II",
    title = "{Measurement of CP asymmetries in B0{\textrightarrow}KS0KS0KS0 decays at Belle II}",
    eprint = "2403.02590",
    archivePrefix = "arXiv",
    primaryClass = "hep-ex",
    reportNumber = "Belle II Preprint 2024-008, KEK Preprint 2023-56",
    doi = "10.1103/PhysRevD.109.112020",
    journal = "Phys. Rev. D",
    volume = "109",
    number = "11",
    pages = "112020",
    year = "2024"
}