{
  "id": "hep-ph/0511161",
  "version": "v2",
  "published": "2005-11-14T03:28:29.000Z",
  "updated": "2005-11-20T09:53:02.000Z",
  "title": "Branching Ratio and CP Asymmetry of $B \\to πη^{(\\prime)}$ Decays in the Perturbative QCD Approach",
  "authors": [
    "Huisheng Wang",
    "Xin Liu",
    "Zhenjun Xiao",
    "Libo Guo",
    "Cai-Dian Lü"
  ],
  "comment": "28 pages, 8 figures, several typos corrected",
  "journal": "Nucl.Phys.B738:243-268,2006",
  "doi": "10.1016/j.nuclphysb.2006.01.021",
  "categories": [
    "hep-ph",
    "hep-ex"
  ],
  "abstract": "We calculate the branching ratios and CP-violating asymmetries for $B^0 \\to \\pi^0 \\eta^{(\\prime)}$ and $B^+\\to \\pi^+ \\eta^{(\\prime)}$ decays in the perturbative QCD (pQCD) factorization approach here. We not only calculate the usual factorizable contributions, but also evaluate the non-factorizable and annihilation type contributions. Besides the current-current operators, the contributions from the QCD and electroweak penguin operators are also taken into account. The pQCD results for the CP-averaged branching ratios are $Br(B^+ \\to \\pi^+ \\eta) \\approx 4.1 \\times 10^{-6}$, $Br(B^+ \\to \\pi^+ \\eta^\\prime) \\approx 2.4 \\times 10^{-6}$, and $Br(B^0 \\to \\pi^0 \\eta^{(\\prime)}) \\approx 0.2 \\times 10^{-6}$, which agree very well with the measured values or currently available experimental upper limits. We also predict large CP-violating asymmetries in these decays: $A_{CP}^{dir}(\\pi^\\pm \\etap)\\sim A_{CP}^{dir}(\\pi^0 \\etap)\\sim -0.35 $, and $A_{CP}^{mix}(\\pi^0 \\etap)\\sim 0.67$, but with large errors. The pQCD prediction for $A_{CP}^{dir}(\\pi^\\pm \\eta)$ ($A_{CP}^{dir}(\\pi^\\pm \\eta^\\prime))$ has the same (opposite) sign with the primary measured values. Further improvements in both theory and experiments are needed to clarify this discrepancy.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2005-11-20T09:53:02.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "12.38.Bx",
      "13.25.Hw",
      "14.40.Nd"
    ],
    "keywords": [
      "branching ratio",
      "perturbative qcd approach",
      "cp asymmetry",
      "annihilation type contributions",
      "electroweak penguin operators"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "publisher": "Elsevier",
      "journal": "Nucl. Phys. B"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 28,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 697869
    }
  }
}