Electroweak baryogenesis via bottom transport: Complementarity between LHC and future lepton collider probes

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 Im(rho(bb)) greater than or similar to 0.058. We find that LHC would probe the nominal Im(rho(bb)) required for baryogenesis to some extent via bg -> bA -> bZh process if 300 GeV less than or similar to m(A) less than or similar to 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 Im(rho(bb)) via e(+)e(-) -> Z* -> AH process followed by A, H -> b (b) over bar over line 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(-) -> Z* -> AH -> Ahh process in six b-jets signature. We find that 1 TeV collision energy with O(1) ab(-1) integrated luminosity could offer an ideal environment for the discovery. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

The study explores the complementarity between the Large Hadron Collider (LHC) and future lepton colliders in probing electroweak baryogenesis induced by an additional bottom Yukawa coupling, with a focus on different detection processes to investigate Im(ρ(bb)), and suggests that a 1 TeV collision energy may offer an ideal environment for discovery.