Searching for heavy Higgs bosons in the t(t)over-barZ and tbW final states

In the context of two-Higgs doublet models, we explore the possibility of searching for heavy Higgs bosons in the t (t) over barZ and tbW final states. We develop realistic analysis strategies and in the case of the t (t) over barZ channel provide a detailed evaluation of the new-physics reach at the 14 TeV LHC. We find that already with an integrated luminosity of 300 fb(-1) searches for the t (t) over barZ signature can provide statistically significant constraints at low values of tan beta for heavy Higgs masses in the range from around 450 GeV to 1150 GeV. Future searches for heavy Higgses in the tbW final state are also expected to be able to probe parts of this parameter space, though the precise constraints turn out to depend sensitively on the assumed systematics on the shape of the t (t) over bar background.