{
  "id": "1506.03416",
  "version": "v1",
  "published": "2015-06-10T18:24:59.000Z",
  "updated": "2015-06-10T18:24:59.000Z",
  "title": "Radiative $μ$ and $τ$ leptonic decays at NLO",
  "authors": [
    "M. Fael",
    "L. Mercolli",
    "M. Passera"
  ],
  "comment": "13 pages, 1 figure, results included as ancillary files",
  "categories": [
    "hep-ph"
  ],
  "abstract": "We present the differential rates and branching ratios of the radiative decays $\\tau \\to l \\bar{\\nu} \\nu \\gamma$, with $l=e$ or $\\mu$, and $\\mu \\to e \\bar{\\nu} \\nu \\gamma$ in the Standard Model at next-to-leading order. Radiative corrections are computed taking into account the full depencence on the mass $m_l$ of the final charged leptons, which is necessary for the correct determination of the branching ratios. Only partial agreement is found with previous calculations performed in the $m_l \\to 0$ limit. Our results agree with the measurements of the branching ratios $\\mathcal{B} (\\mu \\to e \\bar{\\nu} \\nu \\gamma)$ and $\\mathcal{B} (\\tau \\to \\mu \\bar{\\nu} \\nu \\gamma)$ for a minimum photon energy of 10 MeV in the $\\mu$ and $\\tau$ rest frames, respectively. Babar's recent precise measurement of the branching ratio $\\mathcal{B} (\\tau \\to e \\bar{\\nu} \\nu \\gamma)$, for the same photon energy threshold, differs from our prediction by 3.5 standard deviations.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-06-10T18:24:59.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "leptonic decays",
      "branching ratio",
      "minimum photon energy",
      "photon energy threshold",
      "correct determination"
    ],
    "publication": {
      "doi": "10.1007/JHEP07(2015)153",
      "journal": "Journal of High Energy Physics",
      "year": 2015,
      "month": "Jul",
      "volume": 2015,
      "pages": 153
    },
    "note": {
      "typesetting": "TeX",
      "pages": 13,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2015JHEP...07..153F",
      "inspire": 1375510
    }
  }
}