Search for charged Higgs bosons in decays of top quarks

TL;DR

This study searches for charged Higgs bosons in top quark decays within a specific mass range, using collider data, and sets upper limits on their production without observing a signal.

Contribution

First search for charged Higgs bosons in top decays within this mass range using Tevatron data, establishing new exclusion limits.

Findings

No evidence for charged Higgs bosons was found.

Excluded branching ratios for top decays to charged Higgs at 95% confidence level.

Set upper limits on $B(t o H^+b)$ for specified masses.

Abstract

We present a search for charged Higgs bosons in decays of top quarks, in the mass range $80 < m_{H^{\pm} < 155$ GeV, assuming the subsequent decay $H^{+} \to \tau^{+} \nu_\tau$ (and its charge conjugate). Using 0.9 fb$^{-1}$ of lepton+jets data collected with the D0 detector at the Fermilab Tevatron $p\bar{p}$ collider, operating at a center of mass energy $\sqrt{s}=1.96$ TeV, we find no evidence for a $H^{\pm}$ signal. Hence, we exclude branching ratios $B(t \to H^+b) > 0.24$ for $m_{H^{\pm}=80$ GeV, and $B(t \to H^+b) > 0.19$ for $m_{H^{\pm}=155$ GeV, at the 95% C.L.