Tests of light-lepton universality in angular asymmetries of $B^0 \to D^{*-} \ell^+ \nu$ decays

Abstract We present the first comprehensive tests of light-lepton universality in the angular distributions of semileptonic $B^0$-meson decays to charged spin-1 charmed mesons. We measure five angular-asymmetry observables as functions of the decay recoil that are sensitive to lepton-universality-violating contributions. We use events where one neutral $B$ is fully reconstructed in $\Upsilon\left(4S\right)\to{}B \overline{B}$ decays in data corresponding to $189~\mathrm{fb}^{-1}$ integrated luminosity from electron-positron collisions collected with the Belle II detector. We find no significant deviation from the standard model expectations.
Tags
Working group Semileptonic and Missing Energy Decay
Principal authors @  Florian Bernlochner, Michael Eliachevitch, Michael Hedges, Peter Lewis
Reference Phys.Rev.Lett. 131, 181801 (2023), DOI: 10.1103/PhysRevLett.131.181801
Document BELLE2-PUB-PH-2023-017
Links arXiv:2308.02023, Inspire, PRL
Bibtex 
@article{Belle-II:2023svm,
    author = "Adachi, I. and others",
    collaboration = "Belle-II",
    title = "{Tests of Light-Lepton Universality in Angular Asymmetries of B0{\textrightarrow}D*-{\ensuremath{\ell}}{\ensuremath{\nu}} Decays}",
    eprint = "2308.02023",
    archivePrefix = "arXiv",
    primaryClass = "hep-ex",
    reportNumber = "Belle II Preprint 2023-013, KEK Preprint 2023-18",
    doi = "10.1103/PhysRevLett.131.181801",
    journal = "Phys. Rev. Lett.",
    volume = "131",
    number = "18",
    pages = "181801",
    year = "2023"
}