{
  "id": "0902.4295",
  "version": "v2",
  "published": "2009-02-25T06:58:45.000Z",
  "updated": "2009-06-02T05:50:33.000Z",
  "title": "Study of \\bar B\\to Λ_c\\bar Λ_c and \\bar B\\to Λ_c\\bar Λ_c \\bar K",
  "authors": [
    "Hai-Yang Cheng",
    "Chun-Khiang Chua",
    "Yu-Kuo Hsiao"
  ],
  "comment": "16 pages, 3 figures, 3 tables, version to appear in PRD",
  "journal": "Phys.Rev.D79:114004,2009",
  "doi": "10.1103/PhysRevD.79.114004",
  "categories": [
    "hep-ph",
    "hep-ex"
  ],
  "abstract": "We study the doubly charmful two-body and three-body baryonic B decays $\\bar B\\to \\Lambda_c^+\\bar \\Lambda_c^-$ and $\\bar B\\to \\Lambda_c^+\\bar \\Lambda_c^- \\bar K$. As pointed out before, a naive estimate of the branching ratio ${\\cal O}(10^{-8})$ for the latter decay is too small by three to four orders of magnitude compared to experiment. Previously, it has been shown that a large enhancement for the $\\Lambda_c^+\\bar\\Lambda_c^-\\bar K$ production can occur due to a charmonium-like resonance (e.g. X(4630) discovered by Belle) with a mass near the $\\Lambda_c\\bar\\Lambda_c$ threshold. Motivated by the BaBar's observation of a resonance in the $\\Lambda_c \\bar K$ system with a mass of order 2930 MeV, we study in this work the contribution to $\\bar B\\to\\Lambda_c^+\\bar\\Lambda_c^-\\bar K$ from the intermediate state $\\Xi_c(2980)$ which is postulated to be a first positive-parity excited $D$-wave charmed baryon state. Assuming that a soft $q\\bar q$ quark pair is produced through the $\\sigma$ and $\\pi$ meson exchanges in the configuration for $\\bar B\\to \\Xi_c(2980)\\bar\\Lambda_c$ and $\\Lambda_c\\bar\\Lambda_c$, it is found that branching ratios of $\\bar B\\to \\Lambda_c^+\\bar \\Lambda_c^- \\bar K$ and $\\bar B\\to \\Lambda_c^+\\bar \\Lambda_c^-$ are of order $3.5\\times 10^{-4}$ and $5\\times 10^{-5}$, respectively, in agreement with experiment except that the prediction for the $\\Lambda_c\\bar\\Lambda_c K^-$ is slightly smaller. In conjunction with our previous analysis, we conclude that the enormously large rate of $\\bar B\\to \\Lambda_c^+\\bar \\Lambda_c^-\\bar K$ arises from the resonances $\\Xi_c(2980)$ and X(4630).",
  "revisions": [
    {
      "version": "v2",
      "updated": "2009-06-02T05:50:33.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "13.25.Hw",
      "14.40.Nd"
    ],
    "keywords": [
      "branching ratio",
      "wave charmed baryon state",
      "first positive-parity",
      "experiment",
      "large enhancement"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "APS",
      "journal": "Physical Review D",
      "year": 2009,
      "month": "Jun",
      "volume": 79,
      "number": 11,
      "pages": 114004
    },
    "note": {
      "typesetting": "TeX",
      "pages": 16,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 814146,
      "adsabs": "2009PhRvD..79k4004C"
    }
  }
}