Limiting top quark-Higgs boson interaction and Higgs-boson width from multitop productions

Abstract

We demonstrate that the multitop productions efficiently probe the CP property of a top quark-Higgs boson interaction and the Higgs boson width at the LHC. The four top-quark production alone can exclude a purely CP-odd top-quark Yukawa coupling at the 13 TeV LHC with an integrated luminosity of 680 fb-1, regardless the size of the Yukawa coupling. Combining the single Higgs-boson production, the ttH associated production, and the four top-quark production, we show that the CP phase of the top-quark Yukawa coupling and the Higgs-boson width can be stringently bounded at the LHC with integrated luminosities of 300 fb-1 and 3000 fb-1.