{
  "id": "hep-ex/0507096",
  "version": "v1",
  "published": "2005-07-26T08:50:10.000Z",
  "updated": "2005-07-26T08:50:10.000Z",
  "title": "Observation of B^0 -> a_1^{+/-}(1260) π^{-/+}",
  "authors": [
    "Belle Collaboration"
  ],
  "comment": "11 pages, 2 figures",
  "categories": [
    "hep-ex"
  ],
  "abstract": "We report a new measurement of the branching fraction of neutral $B$ meson decays $B^0\\ra a_{1}^{\\pm}(1260)\\pi^{\\mp}$ with \\ensuremath{a_{1}^{\\pm}(1260)\\ra \\rho^{0}\\pi^{\\pm}} and $\\rho^0\\ra pi^+\\pi^-$ using $275\\times 10^{6}$ BBar pairs collected by the Belle detector at the KEKBasymmetric-energy $e^{+}e^{-}$ collider. We measure the branching fraction $\\mathcal{B}($B^0\\ra a_{1}^{\\pm}(1260)\\pi^{\\mp}=(48.6\\pm 4.1(stat)\\pm 3.9(syst)) \\times 10^{-6}$. Using a relativistic Breit-Wigner parameterization, we measure the mass and width of the $a_{1}(1260)$ to be $m_{a_1}=1197\\pm 34 MeV/c^2$ and $\\Gamma_{a_1}=305\\pm 43 MeV/c^2$, respectively.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2005-07-26T08:50:10.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "12.15.Hh",
      "11.30.Er",
      "13.25.Hw",
      "14.40.Nd"
    ],
    "keywords": [
      "observation",
      "branching fraction",
      "belle detector",
      "meson decays"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 688247,
      "adsabs": "2005hep.ex....7096B"
    }
  }
}