{
  "id": "2305.08490",
  "version": "v1",
  "published": "2023-05-15T09:46:25.000Z",
  "updated": "2023-05-15T09:46:25.000Z",
  "title": "Dark sectors and τ physics at Belle II",
  "authors": [
    "Laura Zani"
  ],
  "comment": "contribution to the 2023 QCD session of the 57th Rencontres de Moriond",
  "categories": [
    "hep-ex",
    "hep-ph"
  ],
  "abstract": "The possibility of a dark sector weakly coupling to Standard Model (SM) particles through new light mediators is explored at the Belle II experiment. We present here results from three different searches, for a long-lived (pseudo)scalar particle in rare $B$ decays; for a di-tau resonance in four-muon final states, and the update on the search for a \\zprime\\ boson decaying invisibly. We also look for lepton flavor violation by searching for $\\tau\\rightarrow\\ell \\alpha$ decays, with $\\alpha$ a new invisible boson, and we report the first untagged reconstruction of $\\tau$ pairs events searching for the neutrinoless decays $\\tau \\to \\ell \\phi$. Finally, we present the world's most precise measurement of the $\\tau$ lepton mass. These studies are performed on samples from the data collected by the Belle II detector during 2019-2021 data taking.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-05-15T09:46:25.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "dark sector",
      "four-muon final states",
      "lepton flavor violation",
      "di-tau resonance",
      "standard model"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}