Charged Higgs bosons associated with neutral gauge bosons at future multi--TeV muon colliders

TL;DR

This paper investigates the production of charged Higgs bosons with neutral gauge bosons at future multi-TeV muon colliders within the Two-Higgs-Doublet Model, highlighting potential observability with high significance.

Contribution

It provides updated parameter space, detailed cross section calculations including higher-order corrections, and assesses signal significance for charged Higgs production at muon colliders.

Findings

Production cross sections are significant for several parameter points.

Signals can be observed with >5σ significance at future colliders.

Higher-order corrections improve the accuracy of predictions.

Abstract

The first results for charged Higgs pair production associated with neutral gauge bosons at future multi--TeV muon colliders are presented within the framework of the Two-Higgs-Doublet Model. In the phenomenological studies for the production processes, we first update the parameter space of the Type-X Two-Higgs-Doublet Model. From the viable regions of the parameter space, we compute the production cross sections, including all two-body decay modes of the charged Higgs boson. We mention that all two-body decay modes of the charged Higgs boson are evaluated with one-loop electroweak corrections, with two-loop QCD corrections also included for the decays of the charged Higgs into two fermions. The signal significances are also examined for several benchmark points within the updated parameter space. It is worth emphasizing that the production cross sections used for computing the significances in this work include initial-state radiation corrections up to two-loop order. With the help of the high integrated luminosity planned for future multi--TeV muon colliders, the production signals can be observed with a statistical significance exceeding $5\sigma$ for several selected points within the allowed parameter space.