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Register a new userA signature-based search for delayed photons in exclusive photon plus missing transverse energy events from $p bar{p}$ collisions with $sqrt{s} = 1.96$ TeV
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We present the first signature-based search for delayed photons using an exclusive photon plus missing transverse energy final state. Events are reconstructed in a data sample from the CDF II detector corresponding to $6.3 text{fb}^{-1}$ of integrated luminosity from $sqrt{s}=1.96$ TeV proton-antiproton collisions. Candidate events are selected if they contain a photon with an arrival time in the detector larger than expected from a promptly-produced photon. The mean number of events from standard model sources predicted by the data-driven background model based on the photon timing distribution is $286 pm 24$. A total of 322 events are observed. A $p$-value of 12% is obtained, showing consistency of the data with standard model predictions.
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We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp-bar collisions at sqrt(s)=1.96 TeV corresponding to an integrated luminosity of 6.7/fb recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c^2, and on spin-dependent interactions up to masses of 200 GeV/c^2.
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