Associated Higgs boson production with $Z$ boson in the minimal $U(1)_X$ extended Standard Model

TL;DR

This paper investigates the production of Higgs bosons associated with Z bosons in a minimal U(1)_X extended Standard Model, highlighting the role of a new Z' boson and its potential testability at future colliders.

Contribution

It introduces a novel process for Higgs-Z associated production mediated by a Z' boson in the U(1)_X extension, with detailed calculations of collider signatures.

Findings

New Z' mediated production process identified

Potential collider signatures of the Z' boson analyzed

Implications for future high-energy collider experiments

Abstract

The minimal $U(1)_X$ extension of the Standard Model (SM) is a simple and well-motivated extension of the SM, which supplements the SM with the seesaw mechanism for naturally generating the light neutrino masses and offers various interesting phenomenologies. In the model, the $U(1)_X$ charge of each SM field is characterized by the $U(1)_X$ charge of the SM Higgs doublet with a free parameter $x_H$. Due to the $U(1)_X$ charge of the Higgs doublet, the Higgs boson has a trilinear coupling with the $Z$ boson and the $U(1)_X$ gauge boson ($Z^\prime$). With this coupling, a new process for the associated Higgs boson production with a $Z$ boson arises through a $Z^\prime$ boson in the $s$-channel at high energy colliders. In this paper, we calculate the associated Higgs boson production at high energy colliders and show interesting effects of the new $Z^\prime$ boson mediated process, which can be tested in the future.