Extra $Z^\prime$s and $W^\prime$s in Heterotic--String Derived Models

TL;DR

This paper explores potential extra $Z'$ and $W'$ gauge bosons from heterotic string models that could explain recent ATLAS di-boson excesses, analyzing various model types and their experimental signatures.

Contribution

It systematically surveys heterotic string vacua for extra gauge bosons and examines their phenomenological signatures, including discovery prospects at the LHC.

Findings

Extra $Z'$ and $W'$ bosons can arise in heterotic string models.

Distinct signatures depend on the symmetry breaking scale and model type.

Discovery potential at the LHC is evaluated for certain cases.

Abstract

The ATLAS collaboration recently recorded possible excess in the di--boson production at the di--boson invariant mass at around 2 TeV. Such an excess may be produced if there exist additional $Z^\prime$ and/or $W^\prime$ at that scale. We survey the extra $Z^\prime$s and $W^\prime$s that may arise from semi--realistic heterotic string vacua in the free fermionic formulation in seven distinct cases including: $U(1)_{Z^\prime}\in SO(10)$; family universal $U(1)_{Z^\prime}$ not in $SO(10)$; non--universal $U(1)_{Z^\prime}$; hidden sector $U(1)$ symmetries and kinetic mixing; left--right symmetric models; Pati--Salam models; leptophobic and custodial symmetries. Each case has a distinct signature associated with the extra symmetry breaking scale. In one of the cases we explore the discovery potential at the LHC using resonant leptoproduction. Existence of extra vector boson with the reported properties will significantly constrain the space of allowed string vacua.