We study the complementarity between the Large Hadron Collider (LHC) and future lepton colliders in probing electroweak baryogenesis induced by an additional bottom Yukawa coupling $rho_{bb}$. The context is general two Higgs doublet model (g2HDM) where such additional bottom Yukawa coupling can account for the observed baryon asymmetry of the Universe if $mbox{Im}(rho_{bb}) gtrsim 0.058$. We find that LHC would probe the nominal $mbox{Im}(rho_{bb})$ required for baryogenesis to some extent via $bg to bA to bZh$ process if $300~mbox{GeV}lesssim m_A lesssim 450$ GeV, where $A$ is the CP-odd scalar in g2HDM. We show that future electron positron collider such as International Linear Collider with $500$ GeV and 1 TeV collision energies may offer unique probe for the nominal $mbox{Im}(rho_{bb})$ via $e^+ e^- to Z^*to A H$ process followed by $A,H to b bar b$ decays in four $b$-jets signature. For complementarity we also study the resonant diHiggs productions, which may give an insight into strong first-order electroweak phase transition, via $e^+ e^- to Z^*to A H to A h h$ process in six $b$-jets signature. We find that 1 TeV collision energy with $mathcal{O}(1)~text{ab}^{-1}$ integrated luminosity could offer an ideal environment for the discovery.
Download