A Search for Dimuon Resonances with CDF in Run II

Chris Hays(a), Ashutosh Kotwal(b), Ye Li(c), Oliver Stelzer-Chilton(d)
(a)University of Oxford, (b)Duke University, (c)University of Wisconsin, (d)TRIUMF

Inverse Invariant Mass Spectrum
  • Abstract
  • Measurement Technique
  • Mass Limits for Spin-0 Sneutrino
  • Mass Limits for Spin-1 Z' Models
  • Mass Limits for Spin-2 Graviton Models
  • Mass Limit Tables


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    We present a search for narrow dimuon resonances using 2.3/fb of data collected by the CDF II detector at Run II of the Fermilab Tevatron. No significant excess above the standard model expectation is observed in the dimuon invariant mass spectrum. We set 95% confidence level upper limits on σ⋅Br(pp→X→μμ), where X is a boson with spin 0, 1, or 2. Using these cross section limits, we determine lower mass limits on sneutrinos in R-parity-violating supersymmetric models, Z' bosons, and Kaluza-Klein gravitons in the Randall-Sundrum model.
     Measurement Technique

    At high mass, the observed width of the dimuon invariant mass distribution is dominated by the track curvature resolution, resulting in an approximately constant resolution in δ1/mμμ. Our search strategy is to construct templates of the inverse invariant mass distribution for a range of Z' boson pole masses, add the background distributions to the templates, and compare the templates to the 1/mμμ distribution from data in the search region 1/mμμ < 10 1/TeV. The simulated templates (including backgrounds) are normalized to the data in the 70 GeV < mμμ < 100 GeV normalization region. We evaluate the binned Poisson likelihood as a function of signal template integral. The likelihood yields the best-fit number of signal events observed, as well as the confidence interval.

     Mass Limits for Spin-0 Sneutrino

    • Sneutrino mass limits vs invariant mass: (eps) (gif)

     Mass Limits for Spin-1 Z' Models

     Mass Limits for Spin-2 Graviton Models

    • Graviton mass limits vs invariant mass: (eps) (gif)
     Mass Limit Tables

    Sneutrino Mass Limits

    Z' Mass Limits

    Graviton Mass Limits