Search for the Top Quark Decaying to a Charged Higgs Boson in Antiproton-Proton Collisions at 1.8 Tev

This paper presents the results of a search in overline{p}p collisions at sqrt{s} = 1.8 TeV for the top quark decaying to a charged Higgs boson (H ^+/-) and a bottom quark. We search for dilepton final states from the decay chain t overline{t} to HH (or HW, or WW) + boverline{b} to ll + X. In a sample of 19.3 pb^{-1} collected during 1992-93 with the Collider Detector at Fermilab (CDF), we observe 2 events with a background estimation of 3.0 +/- 1.0 events. Limits at 95% C.L. in the (M_{t}, M _{H}) plane are presented. We also interpret the results in terms of the parameter tan beta of two-Higgs-doublet models.