When the Higgs meets the top: Search for t → ch0 at the LHC

The newly discovered Higgs boson h(0), being lighter than the top quark t, opens up new probes for flavor and mass generation. In the general two Higgs doublet model, new ct, cc and tt Yukawa couplings could modify h(0) properties. If t -> ch(0) occurs at the percent level, the observed ZZ* and gamma gamma signal events may have accompanying cbW activity coming from t (t) over bar feeddown. We suggest that t -> ch(0) can be searched for via h(0) -> ZZ*, gamma gamma, WW* and b (b) over bar, perhaps even tau(+)tau(-) modes in t (t) over bar. events. Existing data might be able to reveal some clues for t -> ch(0) signature, or push the branching ratio B(t -> ch(0)) down to below the percent level. (C) 2013 Elsevier B.V. All rights reserved.