Impact of dark scalars on the radiative $H^+ W^- Z$ vertex

TL;DR

This paper investigates how additional dark matter candidate scalars in an extended two-Higgs doublet model can radiatively enhance the $H^+ W^- Z$ vertex, linking collider interactions with dark matter phenomenology.

Contribution

It extends the two-Higgs doublet model by adding scalars that serve as dark matter candidates and analyzes their impact on the $H^+ W^- Z$ vertex at one-loop level.

Findings

Dark scalars can significantly enhance the $H^+ W^- Z$ interaction.

Dark matter constraints influence the possible strength of the vertex.

The study establishes a connection between dark matter properties and collider observables.

Abstract

An $H^+ W^- Z$ vertex, i.e, the interaction connecting a singly charged physical scalar to the $W^\pm,~Z$ gauge bosons is absent at the tree level in a scalar sector comprising only $SU(2)_L$ doublets. However, the interaction can be generated radiatively in such a case, an example of which is a two-Higgs doublet model. In this study, we extend a two-Higgs doublet scenario by additional $SU(2)_L$ scalar doublets. Upon endowing with appropriate discrete symmetries, these additional doublets so introduced can furnish successful candidates of dark matter. Interestingly, the same "dark" scalars can also radiatively enhance the strength of the $H^+ W^- Z$ interaction. We compute the $H^+ W^- Z$ vertex at one-loop in a non-linear gauge that eliminates certain unphysical interactions. While all possible constraints are taken into account in doing so, particular emphasis is given to the ones stemming from dark matter. Correlations between the dark matter observables and the $H^+ W^- Z$ interaction-strength are studied. The study thus connects a radiatively generated $H^+ W^- Z$ vertex to dark matter phenomenology.