tt¯H Interactions and T-odd Correlations at Hadron Colliders

Abstract

We explore CP -violation effects of Higgs-top interactions in the associated production of a Higgs boson with top-pair in the dileptonic decay modes of top-quark originating from proton proton collisions pp→tt¯H→(l+νlb)(l−νl¯b¯)H at NLO in QCD matched to parton shower via T-odd observables using momenta of various particles involved in the process. In particular, we predict the constraints on the CP -violating tt¯H coupling obtained through the production asymmetries associated with the T-odd observables in the dileptonic decay channel of the tt¯ pair for the Large hadron collider (LHC) with centre-of-mass energy of 13 TeV and an integrated luminosity of 139 fb⁻¹. We also present the corresponding limits for future hadron colliders, namely the High Luminosity LHC (HL-LHC) and the Future Circular Collider (FCC-hh). Our estimates of the tt¯H interaction strength reveal that the upper bound on pseudoscalar coupling c _p corresponding to the largest asymmetry would be of about 1.57 × 10⁻² at 2σ C.L. for c _s = 1 at the LHC with S =13 TeV for an integrated luminosity of 139 fb⁻¹. The respective limits for HL-LHC and FCC-hh with the projected Luminosities of 3 ab⁻¹ and 30 ab⁻¹ are found to be to 2.7 × 10⁻³ and 1.3 × 10⁻⁴ respectively at 2σ C.L.