2HDM Neutral Scalars under the LHC
Abstract
Two Higgs Doublet Models (2HDM) provide a simple framework for new physics models with an extended Higgs sector. The current LHC results, including both direct searches for additional non-Standard Model (SM) Higgs bosons, as well as precision measurements of the SM-like Higgs couplings, already provide strong constraints on the 2HDM parameter spaces. In this paper, we examine those constraints for the neutral scalars in the Type-I and Type-II 2HDM. In addition to the direct search channels with SM final states: H/A f f, VV, Vh, hh, we study in particular the exotic decay channels of H/A AZ/HZ once there is a mass hierarchy between the non-SM Higgses. We found that H/A AZ/HZ channel has unique sensitivity to the alignment limit region which remains unconstrained by conventional searches and Higgs precision measurements. This mode also extends the reach at intermediate β for heavy mA that are not covered by the other direct searches.