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

Abstract

The possibility of a light charged Higgs boson H ± that decays predominantly to quarks (cs and/or cb) and with a mass in the range 80 GeV ≤ m H ± ≤ 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 ± → cb can be dominant in two of the five types of 3HDM, and we determine the parameter space where this occurs. The decay H ± → 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 ≤ m H ± ≤ 90 GeV due to the smaller backgrounds with respect to H ± → cs decays. * Electronic address: a.g.akeroyd@soton.ac.uk † Electronic address: S.Moretti@soton.ac.uk ‡ Electronic address: ms32g13@soton.ac.uk arXiv:1810.05403v1 [hep-ph]

Light charged Higgs boson with dominant decay to a charm quark and a bottom quark and its search at LEP2 and future e+e− colliders

“…The BRs of H ± as functions of the four parameters (tan β, tan γ, θ, δ) have been studied in detail in [18], and the parameter space for a dominant BR(H ± → cb) > 50% was displayed.…”

“…where the values of d, u, and in these matrix elements are given in Tab The experimental constraints on X, Y and Z [20,21] have been summarised in Ref. [18], to which we refer the reader. The parameter space of the 3HDM that is relevant to this work is compliant with all such limits, the most important of which being −1.1 < Re(XY * ) < 0.7…”

“…The first study of the fermionic BRs of H ± as a function of |X|, |Y |, and |Z| was given in [10], with further studies in [12]. In [13,18] these BRs were studied as a function of tan β, tan γ, θ, and δ, an approach which allows the BRs in the five versions of the 3HDM to be compared. For |X| |Y |, |Z| the decay channel BR(H ± → cb) dominates (which was first mentioned in [9]), and reaches a maximum of ∼ 80%.…”

“…For |X| |Y |, |Z| the decay channel BR(H ± → cb) dominates (which was first mentioned in [9]), and reaches a maximum of ∼ 80%. It was shown in [13,18] that such large values of BR(H ± → cb) are only possible in the flipped and democratic 3HDMs, with BR(H ± → cb) having a maximum value of around 1% in the other 3HDMs. In 2HDMs…”

“…At present, the LHC has not set limits in the region 80 GeV ≤ M H ± ≤ 90 GeV if BR(H + → cb) or BR(H + → cs) is dominant, although limits are set for the case of H ± → τ ν being the leading decay channel. As discussed in [18], with the increased luminosity for the data taken at √ s = 13 TeV and with future data it is likely that the LHC will be able to set limits on…”