Measurement of the branching fraction and $CP$ asymmetry of $B^0 \to \pi^0 \pi^0$ decays using $198\times 10^6$ $B\bar{B}$ pairs in Belle II data

Abstract We report measurements of the branching fraction and $\it CP$ asymmetry in $B^{0} \to \pi^{0} \pi^{0}$ decays reconstructed at Belle II in an electron-positron collision sample containing $198 \times 10^{6}$$B\overline{B}$ pairs. We measure a branching fraction $\mathcal{B}(\Bpipi) = (1.38 \pm 0.27 \pm 0.22) \times 10^{-6}$ and a $\it CP$ asymmetry $\Acp(\Bpipi) = 0.14 \pm 0.46 \pm 0.07$, where the first uncertainty is statistical and the second is systematic.
Tags
Working group B Hadronic
Principal authors @  Francis Pham, Martin Sevior
Reference Phys.Rev.D 107, 112009 (2023), DOI: 10.1103/PhysRevD.107.112009
Document BELLE2-PUB-PH-2022-006
Links arXiv:2303.08354, Inspire, PRD
Bibtex 
@article{Belle-II:2023cbc,
    author = "Abudin{\'e}n, F. and others",
    collaboration = "Belle-II",
    title = "{Measurement of the branching fraction and CP asymmetry of B0{\textrightarrow}{\ensuremath{\pi}}0{\ensuremath{\pi}}0 decays using 198{\texttimes}106 BB{\textasciimacron} pairs in Belle II data}",
    eprint = "2303.08354",
    archivePrefix = "arXiv",
    primaryClass = "hep-ex",
    reportNumber = "Belle II Preprint 2023-004, KEK Preprint 2022-59, BELLE2-PUB-DRAFT-2022-006",
    doi = "10.1103/PhysRevD.107.112009",
    journal = "Phys. Rev. D",
    volume = "107",
    number = "11",
    pages = "112009",
    year = "2023"
}