{
  "id": "hep-ph/9812267",
  "version": "v1",
  "published": "1998-12-07T09:58:48.000Z",
  "updated": "1998-12-07T09:58:48.000Z",
  "title": "A Theoretical Reappraisal of Branching Ratios and CP Asymmetries in the Decays $B \\to (X_d,X_s) \\ell^+ \\ell^-$ and Determination of the CKM Parameters",
  "authors": [
    "A. Ali",
    "G. Hiller"
  ],
  "comment": "18 pages, 7 figures (require epsf.sty)",
  "journal": "Eur.Phys.J.C8:619-629,1999",
  "doi": "10.1007/s100520050497",
  "categories": [
    "hep-ph"
  ],
  "abstract": "We present a theoretical reappraisal of the branching ratios and CP asymmetries for the decays $ B \\to X_q \\ell^+ \\ell^-$, with $q=d,s$, taking into account current theoretical uncertainties in the description of the inclusive decay amplitudes from the long-distance contributions, an improved treatment of the renormalization scale dependence, and other parametric dependencies. Concentrating on the partial branching ratios $\\Delta {\\cal B}(B \\to X_q \\ell^+ \\ell^-)$, integrated over the invariant dilepton mass region $1 {GeV}^2 \\leq s \\leq 6 {GeV}^2$, we calculate theoretical precision on the charge-conjugate averaged partial branching ratios $<\\Delta{\\cal B}_q >= (\\Delta {\\cal B}(B \\to X_q \\ell^+ \\ell^-) + \\Delta {\\cal B}(\\bar{B} \\to \\bar{X}_q \\ell^+ \\ell^-))/2$, CP asymmetries in partial decay rates $(a_{CP})_q=(\\Delta {\\cal B}(B \\to X_q \\ell^+ \\ell^-) - \\Delta {\\cal B}(\\bar{B} \\to \\bar{X}_q \\ell^+ \\ell^-))/(2 < \\Delta{\\cal B}_q >)$, and the ratio of the branching ratios $\\Delta {\\cal R} = < \\Delta{\\cal B}_d >/< \\Delta{\\cal B}_s>$. For the central values of the CKM parameters, we find $<\\Delta {\\cal B}_s > =(2.22^{+0.29}_{-0.30}) \\times 10^{-6}$, $<\\Delta {\\cal B}_d > =(9.61^{+1.32}_{-1.47}) \\times 10^{-8}$, $(a_{CP})_s =-(0.19^{+0.17}_{-0.19})%$, $(a_{CP})_d =(4.40^{+3.87}_{-4.46})%$, and $\\Delta {\\cal R} =(4.32 \\pm 0.03)%$. The dependence of $<\\Delta{\\cal B}_d>$ and $\\Delta {\\cal R}$ on the CKM parameters is worked out and the resulting constraints on the unitarity triangle from an eventual measurement of $\\Delta {\\cal R}$ are illustrated.",
  "revisions": [
    {
      "version": "v1",
      "updated": "1998-12-07T09:58:48.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "cp asymmetries",
      "ckm parameters",
      "theoretical reappraisal",
      "invariant dilepton mass region",
      "determination"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 18,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 480604
    }
  }
}