Observation of the decay $B^0 \to J/\psi\,\omega$ at Belle II

Abstract We measure the branching fraction of the decay $B^0 \to J/\psi \omega$ using data collected with the Belle II detector at the SuperKEKB collider. The data contain $(387 \pm 6) \times 10^6$ $B\overline{B}$ meson pairs produced in energy-asymmetric $e^+e^-$ collisions at the $\Upsilon (4S)$ resonance. The measured branching fraction $\mathcal{B}(B^0 \to J/\psi \omega) = \left( 2.16 \pm 0.30 \pm 0.14 \right) \times 10^{-5}$, where the first uncertainty is statistical and the second is systematic, is more precise than previous results and constitutes the first observation of the decay with a significance of $6.5$ standard deviations.
Tags
Working group Radiative and Electroweak Penguin
Principal authors @  Noah Brenny, Chunhui Chen, Michele Veronesi
Reference Phys.Rev.D 111, 032012 (2025), DOI: 10.1103/PhysRevD.111.032012
Document BELLE2-PUB-PH-2024-047
Links arXiv:2412.12338, Inspire, PRD
Bibtex 
@article{Belle-II:2024fgp,
    author = "Adachi, I. and others",
    collaboration = "Belle-II",
    title = "{Observation of the decay B0{\textrightarrow}J/{\ensuremath{\psi}}{\ensuremath{\omega}} at Belle II}",
    eprint = "2412.12338",
    archivePrefix = "arXiv",
    primaryClass = "hep-ex",
    reportNumber = "Belle II preprint: 2024-021, KEK preprint: 2024-18",
    doi = "10.1103/PhysRevD.111.032012",
    journal = "Phys. Rev. D",
    volume = "111",
    number = "3",
    pages = "032012",
    year = "2025"
}