Search for the Charged Higgs Boson in the Decays of Top Quark Pairs in the $e\tau$ and $\mu \tau$ Channels at $\sqrt{s}$=1.8 TeV

Abstract

Top quark production offers the unique opportunity to search for a charged Higgs boson ($H^{\pm }$), as the contribution from $t\to H^{+}b\to {\tau }^{+}\nu b$ can be large in extensions of the Standard Model. We use results from a search for top quark pair production by the Collider Detector at Fermilab (CDF) in the e$τ+ \ebar_T$+jets and $μτ+\ebar_T$+jets signatures to set an upper limit on the branching ratio of $\mathcal{B}(t\to H^{+}b)$ in 106 pb${}^{-1}$ of data. The upper limit is in the range 0.5 to 0.6 at 95% C.L. for $H^{+}$ masses in the range 60 to 160 GeV, assuming the branching ratio for {$H^{+}\to \tau \nu$} is 100% . The $\tau$ lepton is detected through its 1-prong and 3-prong hadronic decays.

Submitted to Phys. Rev. D, 21 pages, 7 figures