{
  "id": "1910.12127",
  "version": "v1",
  "published": "2019-10-26T20:07:17.000Z",
  "updated": "2019-10-26T20:07:17.000Z",
  "title": "Measurement of properties of B$^0_\\mathrm{s}\\toμ^+μ^-$ decays and search for B$^0\\toμ^+μ^-$ with the CMS experiment",
  "authors": [
    "CMS Collaboration"
  ],
  "comment": "Submitted to JHEP. All figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/BPH-16-004 (CMS Public Pages)",
  "categories": [
    "hep-ex"
  ],
  "abstract": "Results are reported for the B$^0_\\mathrm{s}\\to\\mu^+\\mu^-$ branching fraction and effective lifetime and from a search for the decay B$^0\\to\\mu^+\\mu^-$. The analysis uses a data sample of proton-proton collisions accumulated by the CMS experiment in 2011, 2012, and 2016, with center-of-mass energies (integrated luminosities) of 7 TeV (5 fb$^{-1}$), 8 TeV (20 fb$^{-1}$), and 13 TeV (36 fb$^{-1}$). The branching fractions are determined by measuring event yields relative to B$^+\\to$J/$\\psi$K$^+$ decays (with J/$\\psi\\to\\mu^+\\mu^-$), which results in the reduction of many of the systematic uncertainties. The decay B$^0_\\mathrm{s}\\to\\mu^+\\mu^-$ is observed with a significance of 5.6 standard deviations. The branching fraction is measured to be $\\mathcal{B}$(B$^0_\\mathrm{s}\\to\\mu^+\\mu^-$) = [2.9$ ^{+0.7}_{-0.6}$ (exp)$\\pm$0.2(frag)]$\\times 10^{-9}$, where the first uncertainty combines the experimental statistical and systematic contributions, and the second is due to the uncertainty in the ratio of the B$^0_\\mathrm{s}$ and the B$^+$ fragmentation functions. No significant excess is observed for the decay B$^0\\to\\mu^+\\mu^-$, and an upper limit of $\\mathcal{B}$(B$^0\\to\\mu^+\\mu^-$) < 3.6$\\times$10$^{-10}$ is obtained at 95% confidence level. The B$^0_\\mathrm{s}\\to\\mu^+\\mu^-$ effective lifetime is measured to be $\\tau_{\\mu^+\\mu^-}$= 1.70$^{+0.61}_{-0.44}$ ps. These results are consistent with standard model predictions.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-10-26T20:07:17.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "cms experiment",
      "branching fraction",
      "measurement",
      "properties",
      "effective lifetime"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}