LAUSR

The study of the Higgs boson’s properties is a cornerstone of the LHC and future collider programs. In this paper, we examine the potential to directly probe the Higgs-top interaction strength and CP-structure in the t t ¯ h $$ t\overline{t}h $$ channel with the Higgs boson decaying to bottom-quark pairs and top-quarks in the di-leptonic mode. We adopt the BDRS algorithm to tag the boosted Higgs and exploit the M 2 -assisted reconstruction to compute observables sensitive to the CP-phase at the t t ¯ $$ t\overline{t} $$ rest frame, where the new physics sensitivity can be enhanced. Performing a side-band analysis at the LHC to control the continuum t t ¯ b b ¯ $$ t\overline{t}b\overline{b} $$ background, we find that the Higgs-top strength and CP-phase can be probed up to δ κ t $$ {\delta}_{\kappa_t} $$ ≲ 20% and | α | ≲ 36° at 95% CL, respectively. We also derive that a similar analysis at a 100 TeV future collider could further improve the precision to δ κ t $$ {\delta}_{\kappa_t} $$ ≲ 1% and | α | ≲ 1 . 5°, where the CP-odd observables play a crucial role, boosting the sensitivity on the CP-phase.