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

Sumitted to PubDB: 2023-08-11

Category: Physics / performance paper

Tags:

Principal Authors Hanwook Bae, Jakub Kandra, Stefano Lacaprara
Date 2024-12-01
Working group Time Dependent CP Violation
Belle II Number BELLE2-PUB-PH-2023-011
Abstract We describe a measurement of charge-parity ($CP$) violation asymmetries in $B^0\to\eta'K^0_S$ decays using Belle II data. We consider $\eta'\to\eta(\to\gamma\gamma)\pi^+\pi^-$ and $\eta'\to\rho(\to\pi^+\pi^-)\gamma$ decays. The data were collected at the SuperKEKB asymmetric-energy $e^+e^-$ collider between the years 2019 and 2022, and contain $(387\pm 6) \times 10^6$ bottom-antibottom meson pairs. We reconstruct $829\pm35$ signal decays and extract the $CP$ violating parameters from a fit to the distribution of the proper-decay-time difference between the two $B$ mesons. The measured direct and mixing-induced $CP$ asymmetries are $\text{C}_{\eta'K^0_S} = -0.19 \pm 0.08 \pm 0.03 $ and $\text{S}_{\eta'K^0_S} = +0.67 \pm 0.10 \pm 0.04 $, respectively, where the first uncertainties are statistical and the second are systematic. These results are in agreement with current world averages and standard model predictions.
ArXiv https://arxiv.org/abs/2402.03713
Inspire https://inspirehep.net/literature/2755981
DOI 10.1103/PhysRevD.110.112002
Reference Phys.Rev.D 110, 112002 (2024)
Bibtex 
@article{Belle-II:2024xzm,
    author = "Adachi, I. and others",
    collaboration = "Belle-II",
    title = "{Measurement of CP asymmetries in B0{\textrightarrow}{\ensuremath{\eta}}'KS0 decays at Belle II}",
    eprint = "2402.03713",
    archivePrefix = "arXiv",
    primaryClass = "hep-ex",
    reportNumber = "Belle II Preprint 2024-003, KEK Preprint 2023-50",
    doi = "10.1103/PhysRevD.110.112002",
    journal = "Phys. Rev. D",
    volume = "110",
    number = "11",
    pages = "112002",
    year = "2024"
}
Journal Phys.Rev.D

Files