Study of $e^+e^- \to \pi^+ \pi^-\Upsilon(1D)$ at Belle II

Abstract The bottomonium spectrum, consisting of bound states of a $ b $ quark and an anti-$ b $ quark, provides an excellent laboratory for probing quantum chromodynamics in the non-perturbative regime. While S and P-wave bottomonium states are well studied experimentally, information on D-wave states remains scarce. We search for D-wave bottomonium state via the decay of a vector bottomonium-like state $\Upsilon(10753)$ in the reaction $e^+e^- \to \pi^+\pi^- \Upsilon(1D)$, using $19.6~\mathrm{fb}^{-1}$ of data collected with the Belle II detector at center-of-mass energies $\sqrt{s} = 10.653$, 10.701, 10.745, and 10.805~GeV, in the vicinity of the $ \Upsilon(10753) $ resonance. No significant signals are observed. Upper limits at the 90\% credibility level are set on the products of the cross sections and branching fractions, $\sigma[e^+e^- \to \pi^+\pi^- \Upsilon_2(1D)] \times \mathcal{B}(\Upsilon_2(1D) \to \gamma \chi_{b1})$ and $\sigma[e^+e^- \to \pi^+\pi^- \Upsilon_3(1D)] \times \mathcal{B}(\Upsilon_3(1D) \to \gamma \chi_{b2})$, at each center-of-mass energy.
Tags Run 1 (partial)
Working group Quarkonium
Principal authors @  Yong Xie, Junhao Yin, Zhiqing Liu, Sen Jia, Chengping Shen
Reference submitted to JHEP
Links arXiv:2602.19807, Inspire,
Bibtex 
@article{Belle-II:2026oyq,
    author = "Abumusabh, M. and others",
    collaboration = "Belle-II",
    title = "{Study of $e^+e^- \to π^+π^-Υ(1D)$ at Belle II}",
    eprint = "2602.19807",
    archivePrefix = "arXiv",
    primaryClass = "hep-ex",
    month = "2",
    year = "2026"
}