| In this thesis we present the results of a search for Universal Extra Dimensions (UED) with compactification radius near the TeV scale in the multi-lepton channel from proton-antiproton collisions at center-of-mass energy of 1.8 TeV at the Fermi National Accelerator Laboratory. This is the first UED search in the multi-lepton channel performed at the Tevatron.; In the UED scenario, Kaluza-Klein (KK) excitations of Standard Model (SM) particles would be pair produced at the Tevatron and would undergo cascade decays into their zero mode counterparts (SM particles) and the lightest KK particle (LKP). The LKP, the first KK excited photon, is stable and will escape the detector, resulting in a missing energy signature. The signature of the UED scenario we consider is multiple SM leptons, jets and missing energy. We present the result from an analysis of a multi-lepton search using CDF Run IB data corresponding to an integrated luminosity of 87.5 pb-1 . We set an upper limit for the total KK production cross section sigma KK < 7.9 pb at 95% confidence level, corresponding to a minimum extra dimension energy scale of 280 GeV (maximum radius of 3.5 x 10 -19 m). |
