Lawrence Berkeley National Laboratory

We consider search strategies for an extended Higgs sector at the high-luminosity LHC14 utilizing multitop final states. In the framework of a two Higgs doublet model, the purely top final states (tt, 4t) are important channels for heavy Higgs bosons with masses in the wedge above 2mt and at low values of tanβ, while a 2b2t final state is most relevant at moderate values of tanβ. We find, in the ttH channel, with H→tt, that both single and three lepton final states can provide statistically significant constraints at low values of tanβ for mA as high as ∼750 GeV. When systematics on the tt background are taken into account, however, the three lepton final state is more powerful, though the precise constraint depends fairly sensitively on lepton fake rates. We also find that neither 2b2t nor tt final states provide constraints on additional heavy Higgs bosons with couplings to tops smaller than the top Yukawa due to expected systematic uncertainties in the tt background.