HL-LHC and ILC sensitivities in the hunt for heavy Higgs bosons

Abstract

The prediction of additional Higgs bosons is one of the key features of physics beyond the Standard Model (SM) that gives rise to an extended Higgs sector. We assess the sensitivity of the Large Hadron Collider (LHC) in the high luminosity (HL) run alone and in combination with a possible future International Linear Collider (ILC) to probe heavy neutral Higgs bosons. We employ the Minimal Supersymmetric Standard Model (MSSM) as a framework and assume the light $$\mathcal {CP}$$ CP -even MSSM Higgs boson to be the Higgs boson observed at $$125\,\mathrm{GeV}$$ 125 GeV . We discuss the constraints on the MSSM parameter space arising from the precision measurements of the rates of the detected signal at $$125\,\mathrm{GeV}$$ 125 GeV and from direct searches for new heavy Higgs bosons in the $$\tau ^+\tau ^-$$ τ + τ - , $$b\bar{b}$$ b b ¯ and di-Higgs (hh) final states. A new benchmark scenario for heavy Higgs searches in the $$b\bar{b}$$ b b ¯ channel is proposed in this context. For the future Higgs rate measurements at the HL-LHC and ILC two different scenarios are investigated, namely the case where the future rate measurements agree with the SM prediction and the case where the rates agree with the predictions of possible realizations of the MSSM Higgs sector in nature.

Possible indications for new Higgs bosons in the reach of the LHC: N2HDM and NMSSM interpretations

“…7 Hence, the signal-rate measurements of h 125 at the LHC, which at the present level of accuracy show no significant deviations from the SM prediction, can be cast into a lower limit on M A . Taking into account the most recent LHC results [69,70], the current limit was found to be M A 600 GeV, (largely) independently of the value of tan β [68,71]. Consequently, the MSSM cannot account for the presence of a CP-odd Higgs boson state around 400 GeV without being in strong tension with the signal rates of h 125 , and a SUSY interpretation of the observed excesses therefore needs to be based on non-minimal SUSY models.…”

The tiny (g-2) muon wobble from small-μ supersymmetry

“…For this suppression to be effective, the masses of the non-SM-like Higgs bosons must be low enough to within the reach (see, for example, ref. [218]) of future runs of the LHC: the high-luminosity LHC will be sensitive to Higgs bosons with masses of about a factor 1.5 larger than current exclusion limits (keeping all other parameters, in particular tan β, fixed). From the expression of the SIDD cross section, eq.…”

Possible indications for new Higgs bosons in the reach of the LHC: N2HDM and NMSSM interpretations

“…9 Hence, the signal-rate measurements of h 125 at the LHC, which at the present level of accuracy show no significant deviations from the SM prediction, can be cast into a lower limit on M A . Taking into account the most recent LHC results [5,74], the current limit was found to be M A 600 GeV, (largely) independently of the value of tan β [73,75]. Consequently, the MSSM cannot account for the presence of a CP-odd Higgs boson state around 400 GeV without being in strong tension with the signal rates of h 125 , and a SUSY interpretation of the observed excesses therefore needs to be based on nonminimal SUSY models.…”