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

TL;DR

This paper searches for charged Higgs bosons in top quark decays using Fermilab data, setting upper limits on the decay branching ratio for various Higgs masses in specific decay channels.

Contribution

It provides the first upper limits on the branching ratio of top quark decays to charged Higgs bosons in eτ and μτ channels at Fermilab energies.

Findings

Upper limit on ${ m BR}(t o H^+b)$ is 0.5-0.6 at 95% C.L.

Limits are set for $H^+$ masses between 60 and 160 GeV.

Assumes ${H^+ o au u}$ branching ratio is 100%.

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$\tau + \ebar_T$+jets and $\mu\tau +\ebar_T$+jets signatures to set an upper limit on the branching ratio of ${\cal B} (t \to H^{+} b)$ 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.