{
  "id": "1612.03291",
  "version": "v1",
  "published": "2016-12-10T13:13:59.000Z",
  "updated": "2016-12-10T13:13:59.000Z",
  "title": "$τ^-\\toη^{(\\prime)}π^-ν_τγ$ decays as backgrounds in the search for second class currents",
  "authors": [
    "A. Guevara",
    "G. López-Castro",
    "P. Roig"
  ],
  "comment": "60 pages, 28 figures and 2 tables",
  "categories": [
    "hep-ph",
    "hep-ex"
  ],
  "abstract": "Observation of $\\tau^-\\to\\eta^{(\\prime)}\\pi^-\\nu_\\tau $ decays at Belle-II would indicate either a manifestation of isospin symmetry breaking or genuine second class currents (SCC) effects. The corresponding radiative $\\tau^-\\to\\eta^{(\\prime)}\\pi^-\\nu_\\tau \\gamma$ decay channels are not suppressed by $G$-parity considerations and may represent a serious background in searches of SCC in the former. We compute the observables associated to these radiative decays using Resonance Chiral Lagrangians and conclude that vetoing photons with $E_\\gamma>100$ MeV should get rid of this background in the Belle-II environment searching for the $\\tau^-\\to\\eta \\pi^-\\nu_\\tau $ channel. Similar considerations hold inconclusive for decays involving the $\\eta^\\prime$ given the theory uncertainties in the prediction of the $\\tau^-\\to\\eta^\\prime\\pi^-\\nu_\\tau$ branching ratio. Still, additional kinematics-based cuts should be able to suppress this background in the $\\eta^\\prime$ case to a negligible level.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2016-12-10T13:13:59.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "background",
      "genuine second class currents",
      "resonance chiral lagrangians",
      "similar considerations hold",
      "decay channels"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 60,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}