Search for Extra Dimensions in Jets+Missing Energy in RunII


Events with large missing transverse energy and one or more energetic jets can be produced in many models of new physics, in addition to standard model production from electroweak and QCD processes. One model of new physics that can produce such a signature is the compactified Large Extra Dimensions (LED) model of Arkani-Hamed, Dimopoulos, and Dvali (ADD). In such a model, gravitons are produced directly in processes such as qqbar->gG, qg->qG, or gg->gG, where G is the emitted graviton. The emitted graviton will be undetected, leaving the final state quark or gluon to produce a jet. In all cases, the signature will be jets plus missing energy.
We present the result of a generic search for new physics based on ~1.0fb-1 of data collected with the missing Et trigger path (MET > 45 GeV) using kinematic cuts of Et > 80 GeV on the leading jet and MET > 80 GeV. We also present the result of a more optimized search for LED based on ~1.1fb-1 of data collected with the inclusive jet trigger path (jet Et > 100 GeV) using kinematic cuts of Et > 150 GeV for the leading jet and MET > 120 GeV. In both analyses, a comparison is made between the observed data and expected backgrounds. Using the results of our generic search, we extract a direct measurement of the invisible width of the Z boson. Limits on the LED model are obtained from the optimized search.

Kevin Burkett, Eric James
Pierre-Hughes Beauchemin, Pierre Savard
University of Toronto

  • Contact people : Eric, Hugo, Kevin, Pierre

  • Generic Search for New Physics:
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  • Optimized Search for LED:
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  • Last updated : July 30, 2007