Abstract The first results for charged Higgs pair production associated with a neutral gauge boson at future multi-TeV muon colliders are presented within the framework of the Two-Higgs-Doublet Model (THDM). In this phenomenological study, we update the viable parameter space of the Type-X and Type-II THDM. All two-body decay channels of the charged Higgs boson are then evaluated with the help of. The dominant branching fractions of the charged Higgs decay modes are shown within the allowed parameter space of the considered models. The production cross sections also include initial-state radiation corrections up to two-loop order in this work. The signal significances for the production processes are then examined by scanning over the viable parameter space of the models. With the high integrated luminosity planned for future multi-TeV muon colliders, the production signals can be observed with a statistical significance exceeding 5 5 σ for several selected points within the allowed parameter space.
Phan et al. (2026) studied this question.