Exotic Higgs Decays in Type-II 2HDMs at the LHC and Future 100 TeV Hadron Colliders

Abstract: The exotic decay modes of non-Standard Model (SM) Higgses in models with extended Higgs sectors have the potential to serve as powerful search channels to explore the space of Two-Higgs Doublet Models (2HDMs) that cannot be studied effectively using conventional decay channels. Once kinematically allowed, heavy Higgses could decay into pairs of light non-SM Higgses, or a non-SM Higgs and a SM gauge boson, with branching fractions that dominate those of the conventional decay modes to SM particles. In this study, we focus on the prospects of probing exotic decay channels at the LHC and a future 100 TeV \emph{pp} collider in the context of Type-II 2HDMs. We study the three prominent exotic decay channels, A -> HZ, A -> H^+ W and H^+ -> HW, and find that a 100-TeV pp collider can probe the entire region of the Type-II 2HDM parameter space that survives current theoretical and experimental constraints with exotic decay branching fraction > 20%.