Search for the production of dark Higgs in the framework of Mono-Z${}^{\mathrm{\prime }}$ portal at the FCC-ee simulated electron-positron collisions at $\sqrt{s}=240$ GeV

In the present work, we study the possible production of the dark Higgs boson ($h_D$) candidates, which originated from a simplified-model scenario based on the Mono-Z${}^{\mathrm{\prime }}$ model, in association with a neutral gauge boson (Z${}^{\mathrm{\prime }}$). This study has been performed by studying events with dimuon plus missing transverse energy produced in the simulated electron-positron collisions at the foreseen Future Circular Collider in the Electron-Positron collision mode (FCC-ee), operating at 240 GeV center of mass energy and integrated luminosity of 10.8 ab${}^{-1}$. In case no new physics has been discovered, we set upper limits at a 95% confidence level on the mass of the dark Higgs.