One-loop expressions for $H^{\pm }\to W^{\pm }Z$ and their implications at muon--TeV colliders

Abstract

One-loop contributions for decay process $H^{\pm }\to W^{\pm }Z$ within the Two-Higgs-Doublet Model are computed in the general ${\mathcal{R}}_{\xi }$ gauge, and its phenomenological applications at future muon--TeV colliders are studied in this paper. The analytic results are confirmed by several consistency tests, for example, the $\xi$-independence, the renormalization-scale stability and the ultraviolet finiteness of the one-loop amplitude. We first perform an updated parameter scan of the Type-X THDM in the phenomenological studies. The production of charged Higgs boson pairs at future muon--TeV colliders is investigated through the two processes ${\mu }^{+}{\mu }^{-}\to H^{+}{H}^{-}\to W^{\pm }{W}^{\mp }Zh$ and ${\mu }^{+}{\mu }^{-}\to \gamma \gamma \to H^{+}{H}^{-}\to W^{\pm }{W}^{\mp }Zh$. Both signal events and their significances are evaluated with taking into account the corresponding Standard Model backgrounds. We find that the signal significances can exceed $5\sigma$ at several benchmark points in the viable parameter space of the Type-X THDM.

Comments: 32 pages, 5 Tables of data, 5 Figures