Probing the general 2HDM with flavor violation through $A\to ZH$

We investigate the LHC discovery prospects for a second Higgs doublet through $A\to ZH$ weak decay. The latter is identified as the $\mathit{\text{smoking}}\mathit{\text{gun}}\mathit{\text{signature}}$ of two Higgs doublet models (2HDMs) with first-order electroweak (EW) phase transition, a necessary condition for EW baryogenesis. In the general 2HDM (G2HDM) that has flavor-changing neutral Higgs couplings, $H$ may decay dominantly via $t\bar{c}+\bar{t}c$ final states, giving rise to trilepton signals. By a phenomenological analysis, we show that $A\to ZH$ in ${\mathrm{\ell }}^{+}{\mathrm{\ell }}^{-}t\bar{c}$ or ${\mathrm{\ell }}^{+}{\mathrm{\ell }}^{-}\bar{t}c$ final states could be a promising probe of G2HDM at the LHC with flavor violation.