Light charged Higgs bosons to AW/HW via top decay

Abstract

While current ATLAS and CMS measurements exclude a light charged Higgs (m H ± < 160 GeV) for most of the parameter region in the context of the MSSM scenarios, these bounds are significantly weakened in the Type II 2HDM once the exotic decay channel into a lighter neutral Higgs, H ± → AW/HW , is open. In this study, we examine the possibility of a light charged Higgs produced in top decay via single top or top pair production, which is the most prominent production channel for a light charged Higgs at the LHC. We consider the subsequent decay H ± → AW/HW , which can reach a sizable branching fraction at low tan β once it is kinematically permitted. With a detailed collider analysis, we obtain exclusion and discovery bounds for the 14 TeV LHC assuming the existence of a 70 GeV neutral scalar. Assuming BR(H ± → AW/HW ) = 100% and BR(A/H → τ τ ) = 8.6%, the 95% exclusion limits on BR(t → H + b) are about 0.2% and 0.03% for single top and top pair production respectively, with an integrated luminosity of 300 fb −1 . The discovery reaches are about 3 times higher. In the context of the Type II 2HDM, discovery is possible at both large tan β > 17 for 155 GeV < m H ± < 165 GeV, and small tan β < 6 over the entire mass range. Exclusion is possible in the entire tan β versus m H ± plane except for charged Higgs masses close to the top threshold. The exotic decay channel H ± → AW/HW is therefore complementary to the conventional H ± → τ ν channel.

Let there be light from a second light Higgs doublet

“…We are also grateful to Martin Bauer for interesting discussions concerning electroweak precision measurements and his encouragement, and would like to thank Fady Bishara for help with ROOT as well as Chris Hays and Mika Vesterinen for useful communications concerning lepton non-universality in W decays. We are thankful as well to Andrew Akeroyd, Giacomo Cacciapaglia, Junjie Cao and Felix Kling for their positive feedback and making us aware of [18,[20][21][22][23][24][25][26]78]. We finally would like to express our gratitude to Andrew Akeroyd for drawing our attention to the process pp → W ± * → H ± H and pointing out that under certain circumstances it can be phenomenologically relevant.…”

“…Examples of Feynman graphs that can give rise to H production in 2HDMs via a cascade or in association with a charged Higgs are displayed in figure 1. We emphasise that while the first two aforementioned production mechanism have been discussed in [15], the third and fourth channel has not been considered in the latter paper -the possible importance of cascades and associated H ± H production in 2HDMs has however been stressed before in the literature [19][20][21][22][23][24][25][26]. In order to illustrate the four production mechanism and the resulting phenomenology, we discuss a specific benchmark scenario in each case.…”

Status of the charged Higgs boson in two Higgs doublet models

“…For further discussion of the collider search prospects for this signature see Refs. [174][175][176].…”

Relaxed constraints on the heavy scalar masses in 2HDM

“…Thus it is possible to constrain the parameter space of the type-II 2HDM even at the alignment limit from the non-observation of the heavier scalars [23] [53,54]. In general, the importance of Higgs cascade decays as the possible probes of an extended scalar sector have been discussed in the literature [55][56][57][58][59][60] and A → ZH decay is dubbed as a 'golden channel' in this context [61].…”