Exploring the anomalous Higgs-top couplings

The top quark with its large Yukawa coupling is crucially important to explore TeV scale physics. Therefore, the study of the Higgs-top sector is highly motivated to look for any deviations from the standard model predictions. The most general lowest-order Lagrangian for the Higgs-top Yukawa coupling has scalar (kappa) and pseudoscalar (kappa) over tilde components. Currently, these couplings are constrained indirectly using the present experimental limits on the Higgs-gamma-gamma and Higgs-gluon-gluon couplings. Furthermore, stronger bounds on kappa and (kappa) over tilde are obtained using the limits on the electric dipole moments (EDM). In this paper, we propose an asymmetrylike observable O-phi in t (t) over barH production at the LHC to probe the Higgs-top coupling and to distinguish between the scalar and pseudoscalar components. We also show that the presence of the pseudoscalar component in the Higgs-top Yukawa coupling leads to a sizeable value for the top quark EDM. It is shown that a limit of 10-19 e.cm, which is achievable by the future e(-)e(+) collider, allows us to exclude a significant region in the (kappa, (kappa) over tilde) plane.