Search for Supersymmetry inpp¯Collisions ats=1.96TeVUsing the Trilepton Signature for Chargino-Neutralino Production

We use the three lepton and missing energy trilepton signature to search for chargino-neutralino production with $2.0{\mathrm{fb}}^{-1}$ of integrated luminosity collected by the CDF II experiment at the Tevatron $p\overline{p}$ collider. We expect an excess of approximately 11 supersymmetric events for a choice of parameters of the mSUGRA model, but our observation of 7 events is consistent with the standard model expectation of 6.4 events. We constrain the mSUGRA model of supersymmetry and rule out chargino masses up to $145\mathrm{GeV}/c^2$ for a specific choice of parameters.