Implications of CP-violating top-Higgs couplings at the LHC and Higgs factories

摘要

We utilize the LHC run-1 and -2 Higgs data to constrain the CP-violating top-Higgs couplings. In order to satisfy the current full Higgs data sets at 2σ level, the CP-odd component C_t~p and the CP-even component Q have to be within the ranges |C_t~p| ＜ 0.37 and 0.85 ＜ Q < 1.20, respectively, which is stronger than the LHC run-1 bound |C_t~p| ＜ 0.54 and 0.68 ＜ C_t~s ＜ 1.20. With the new bound, we explore the impact on the CP-violating top-Higgs couplings in the Higgs production processes pp → tth, thj, hh at 13 TeV LHC, and e~+e -→ hZ, hγ at future 240 GeV Higgs factories. We find that the cross sections of pp → tth, pp → thj, pp → hh, e~+e~-→ hZ and e~+e~-→ hγ can be enhanced up to 1.41, 1.18, 2.20, 1.001 and 1.09 times as large as the SM predictions, respectively. The future precision measurement of the process e~+e~-→ hγ with an accuracy of 5% will be able to constrain |C_t~p| ＜ 0.19 at most at a 240 GeV e~+e~- Higgs factory.