Fermiophobic gauge boson phenomenology in 221 Models

TL;DR

This paper explores the collider signatures of a fermiophobic $Z'$ gauge boson in extended gauge models, emphasizing vector boson fusion production and decay into $WW$ or $Zh$, with analysis for LHC and CLIC.

Contribution

It introduces a novel collider search strategy for fermiophobic $Z'$ bosons via vector boson fusion, focusing on $ ext{ll}bb$ final states, and provides optimized discovery criteria.

Findings

Fermiophobic $Z'$s are discoverable in $ ext{ll}bb$ channel at LHC.

Optimized kinematic cuts improve discovery potential.

Results apply to a wide parameter space of the model.

Abstract

Models with extra gauge symmetry are well-motivated extensions of the Standard Model. In this paper, we study an extended gauge model with a heavy neutral gauge boson $Z'$ which is fermiophobic. Thus, the production of such particles can occur via vector boson fusion, with subsequent decays into $WW$ or $Zh$. We investigate the collider phenomenology of such $Z'$s in the context of both the 14 TeV LHC and the future CLIC. We find that looking at $\ell\ell b b$ final states provides a rich opportunity to discover such new vector bosons where conventional search strategies in the dilepton channel would fail. In particular, we optimize our analysis by putting in kinematic cuts deriving model-independent values of $\sigma\times$BR needed for a 5$\sigma$ discovery at the LHC. We then translate this into the parameter space of a specific model for illustration purpose -- our results show that fermiophobic $Z'$s are discoverable in the $\ell\ell b b$ channel for wide range of parameter values.