Identifying a light charged Higgs boson at the LHC Run II

摘要

We analyse the phenomenological implications of a light Higgs boson, h , within the CP-conserving 2-Higgs Doublet Model (2HDM) Type-I, for the detection prospects of the charged H ± state at Run II of the Large Hadron Collider (LHC), assuming s = 13 TeV as energy and O ( 100 ? fb ? 1 ) as luminosity. When sufficiently light, this h state can open up the bosonic decay channel H ± → W ± ( ? ) h , which may have a branching ratio significantly exceeding those of the H ± → τ ν and H ± → c s channels. We perform a broad scan of the 2HDM Type-I parameter space, assuming the heavier of the two CP-even Higgs bosons, H , to be the observed SM-like state with a mass near 125 GeV. Through these scans we highlight regions in which m H ± < m t + m b that are still consistent with the most recent limits from experimental searches. We find in these regions that, when the H ± → W ± ( ? ) h decay mode is the dominant one, the h can be highly fermiophobic, with a considerably large decay rate in the γγ channel. This can result in the total cross section of the σ ( p p → H ± h → W ± ( ? ) + 4 γ ) process reaching up to O ( 100 ? fb ) . We therefore investigate the possibility of observing this spectacular signal at the LHC Run II.