Prospect and implications of $cgto bH^+to b A W^+$ production at the LHC

We study the prospect for discovering the $cgto bH^+to b A W^+$ process at the LHC. Induced by the top-flavor changing neutral Higgs coupling $rho_{tc}$, the process may emerge if $m_{H^+} > m_A + m_{W^+}$, where $H^+$ and $A$ are charged and $CP$-odd Higgs bosons in the general two Higgs Doublet Model (g2HDM). We show that the $cgto bH^+to b A W^+$ process can be discovered at LHC Run 3, while the full Run 2 data at hand can constrain the parameter space significantly by searching for the same-sign dilepton final state. The process has unique implications on the hint of $ggto A to t bar t$ excess at $m_Aapprox 400$ GeV reported by CMS. When combined with other existing constraints, the $cgto bH^+to b A W^+$ process can essentially rule out the g2HDM explanation of such an excess.