Multi-lepton signals of multiple Higgs bosons

We identify and investigate novel multi-lepton signatures of extended Higgs sectors at the LHC in the guise of CP- and flavor-conserving two-Higgs-doublet models (2HDMs). Rather than designing individual searches tailored to specific 2HDM signals, we employ the combination of many exclusive multi-lepton search channels to probe the collective signal from the totality of production and decay processes. Multi-lepton signals of 2HDMs can arise from a variety of sources, including Standard Model-like production of the CP-even scalars, h and H, through gluon-fusion with h, H -> ZZ(*), or associated production with vector bosons or top quarks, with h, H -> WW(*), ZZ(*), tau tau. Additional sources include gluon-fusion production of the heavy CP-even scalar with cascade decays through the light CP-even scalar, the CP-odd scalar, A, or the charged scalar, H-+/-, such as H -> hh, H -> AA, H -> H+H-, H -> ZA with A -> Zh, tau tau, H-+/- -> Wh, and h -> WW*, ZZ*, tau tau. Altogether, the combined multi-lepton signal may greatly exceed that of the Standard Model Higgs boson and provides a sensitive probe of extended Higgs sectors over a wide range of parameters. As a proof of principle, we use a factorized mapping procedure between model parameters and signatures to determine multi-lepton sensitivities in four different flavor conserving 2HDM parameter spaces by simulating the acceptance times efficiency in 20 exclusive multi-lepton channels for 222 independent production and decay topologies that arise for four benchmark 2HDM spectra within each parameter space. A comparison of these sensitivities with the results of a multi-lepton search conducted by the CMS collaboration using 5 fb(-1) of data collected from 7 TeV pp collisions yields new limits in some regions of 2HDM parameter space that have not previously been covered by other types of direct experimental searches.