Light charged Higgs boson with dominant decay to quarks and its search at LHC and future colliders

TL;DR

This paper investigates the potential for a light charged Higgs boson decaying mainly to quarks within Three-Higgs-Doublet Models, highlighting current experimental constraints and prospects for future collider searches.

Contribution

It identifies parameter regions where the $H^\pm o cb$ decay dominates and assesses the LHC's sensitivity to this scenario in the 80-90 GeV mass range.

Findings

The $H^\pm o cb$ decay can be dominant in certain 3HDM types.

Current constraints are from LEP2 and Tevatron, with limited LHC sensitivity.

Future LHC searches with more data could detect this decay mode.

Abstract

The possibility of a light charged Higgs boson $H^\pm$ that decays predominantly to quarks ($cs$ and/or $cb$) and with a mass in the range 80 GeV $\le m_{H^\pm} \le 90$ GeV is studied in the context of Three-Higgs-Doublet Models (3HDMs). At present the Large Hadron Collider (LHC) has little sensitivity to this scenario, and currently the best constraints are from LEP2 and Tevatron searches. The branching ratio of $H^\pm\to cb$ can be dominant in two of the five types of 3HDM, and we determine the parameter space where this occurs. The decay $H^\pm\to cb$ has recently been searched for at the LHC for the first time, and with increased integrated luminosity one would expect sensitivity to the region 80 GeV $\le m_{H^\pm} \le 90$ GeV due to the smaller backgrounds with respect to $H^\pm\to cs$ decays.