| This dissertation reports the results of a search for charged Higgs bosons in the decays of tt¯ pairs produced in pp¯ collisions at a center-of-mass energy of 1.96 TeV. The search is performed on a data sample recorded by the upgraded Collider Detector at Fermilab and corresponding to an integrated luminosity of 193 pb-1.; The search is based on the relative rates of events in the different tt¯ decay channels. Results are obtained in the context of different models. In the context of the minimal supersymmetric extension of the Standard Model (MSSM), for which we fully account for radiative and Yukawa coupling corrections, regions in the (mH+/-,tan(beta)) plane are excluded. In the Tauonic Higgs Model in which the charged Higgs is assumed to decay exclusively to taunu, the BR(t → H+b) is constrained to be less than 0.4 at 95% C.L. If no assumption is made on the charged Higgs decay, the BR(t → H+b) is constrained to be less than 0.90 at 95% C.L. No evidence for charged Higgs production is found. |
