Fermion pair production at $e^- e^+$ linear collider experiments in GUT inspired gauge-Higgs unification

TL;DR

This paper investigates fermion pair production at future $e^-e^+$ linear colliders within a GUT-inspired gauge-Higgs unification model, highlighting large parity violation effects from KK excitations detectable at multi-TeV scales.

Contribution

It demonstrates the potential to observe distinctive polarization-dependent signals from KK modes in gauge-Higgs unification models at upcoming collider energies.

Findings

Large parity violation in lepton and quark couplings to KK $Z'$ bosons.

Detectable effects up to KK mass scale of about 15 TeV.

Significant polarization asymmetries in collider processes.

Abstract

Fermion pair production at $e^-e^+$ linear collider experiments with polarized $e^-$ and $e^+$ beams is examined in the GUT inspired $SO(5)\times U(1)\times SU(3)$ gauge-Higgs unification. There arises large parity violation in the couplings of leptons and quarks to Kaluza-Klein (KK) excited neutral vector bosons $Z'$s, which leads to distinctive polarization dependence in cross sections, forward-backward asymmetries, left-right asymmetries, and left-right forward-backward asymmetries in various processes. Those effects are detectable even for the KK mass scale up to about 15 TeV at future $e^-e^+$ linear collider experiments with energies 250$\,$GeV to 1$\,$TeV.