$Z'$, Higgses and heavy neutrinos in $U(1)'$ models: from the LHC to the GUT scale

TL;DR

This paper explores minimal $U(1)'$ extensions of the Standard Model, analyzing their theoretical consistency, experimental constraints, and potential signals at the LHC, linking low-energy measurements to grand unification theories.

Contribution

It provides a comprehensive analysis of the parameter space, stability, and phenomenology of $U(1)'$ models, including scalar and gauge mixing effects, with implications for collider searches.

Findings

Identifies viable parameter regions consistent with current constraints.

Highlights key collider signatures of heavy neutrinos, Higgs states, and $Z'$ bosons.

Connects collider phenomenology to grand unification scale physics.

Abstract

We study a class of non-exotic minimal $U(1) '$ extensions of the Standard Model, which includes all scenarios that are anomaly-free with the ordinary fermion content augmented by one Right-Handed neutrino per generation, wherein the new Abelian gauge group is spontaneously broken by the non-zero Vacuum Expectation Value of an additional Higgs singlet field, in turn providing mass to a $Z'$ state. By adopting the $B-L$ example, whose results can be recast into those pertaining to the whole aforementioned class, and allowing for both scalar and gauge mixing, we first extract the surviving parameter space in presence of up-to-date theoretical and experimental constraints. Over the corresponding parameter configurations, we then delineate the high energy behaviour of such constructs in terms of their stability and perturbativity. Finally, we highlight key production and decay channels of the new states entering the spectra of this class of models, i.e., heavy neutrinos, a second Higgs state and the $Z'$, which are amenable to experimental investigation at the Large Hadron Collider. We therefore set the stage to establish a direct link between measurements obtainable at the Electro-Weak scale and the dynamics of the underlying model up to those where a Grand Unification Theory embedding a $U(1)'$ can be realised.