Higgs bosons of a supersymmetric $U(1)'$ model at the ILC

TL;DR

This paper investigates the Higgs sector of a supersymmetric model with an extra U(1) gauge symmetry, highlighting how Higgs couplings to Z bosons differ from the standard model and can be tested at the ILC.

Contribution

It demonstrates that the sum of squared Higgs-Z couplings in this model is less than one, providing a distinctive signature to differentiate it from the NMSSM at future colliders.

Findings

Sum of squared Higgs-Z couplings is less than unity in the model.

Potential to distinguish models via Higgs coupling measurements at the ILC.

Higgs production via Higgs-strahlung, ZZ fusion, and WW fusion processes.

Abstract

We study the scalar Higgs sector of the next-to-minimal supersymmetric standard model with an extra U(1), which has two Higgs doublets and a Higgs singlet, in the light leptophobic $Z'$ scenario where the extra neutral gauge boson $Z'$ does not couple to charged leptons. In this model, we find that the sum of the squared coupling coefficients of the three neutral scalar Higgs bosons to $ZZ$, normalized by the corresponding SM coupling coefficient is noticeably smaller than unity, due to the effect of the extra U(1), for a reasonable parameter space of the model, whereas it is unity in the next-to-minimal supersymmetric standard model. Thus, these two models may be distinguished if the coupling coefficients of neutral scalar Higgs bosons to $ZZ$ are measured at the future International Linear Collider by producing them via the Higgs-strahlung, $ZZ$ fusion, and $WW$ fusion processes.