Flavor changing heavy Higgs interactions at the LHC

A general two Higgs doublet model (2HDM) is adopted to study the signature of flavor changing neutral Higgs (FCNH) decay ϕ0→tc¯+t¯c, where ϕ0ϕ0 could be a CP-even scalar (H0H0) or a CP-odd pseudoscalar (A0A0). Measurement of the light 125 GeV neutral Higgs boson (h0h0) couplings at the Large Hadron Collider (LHC) favor the decoupling limit or the alignment limit of a 2HDM, in which gauge boson and diagonal fermion couplings of h0h0 approach Standard Model values. In such limit, FCNH couplings of h0h0 are naturally suppressed by a small mixing parameter cos⁡(β−α)cos⁡(β−α), while the off-diagonal couplings of heavier neutral scalars ϕ0ϕ0 are sustained by sin⁡(β−α)∼1sin⁡(β−α)∼1. We study physics background from dominant processes with realistic acceptance cuts and tagging efficiencies. Promising results are found for the LHC running at 13 or 14 TeV collision energies.