New Signatures of Flavor Violating Higgs Couplings

Understand

We explore several novel LHC signatures arising from quark or lepton flavor violating couplings in the Higgs sector, and we constrain such couplings using LHC data.

• Since the largest signals are possible in channels involving top quarks or tau leptons, we consider in particular the following flavor violating processes: (1) $pp \to thh$ (top plus di-Higgs final state) arising from a dimension six coupling of up-type quarks to three insertions of the Higgs field.
• We develop a search strategy for this final state and demonstrate that detection is possible at the high luminosity LHC if flavor violating top--up--Higgs couplings are not too far below the current limit.
• (2) $pp \to tH^0$, where $H^0$ is the heavy neutral CP-even Higgs boson in a two Higgs doublet model (2HDM).