Toward Realistic Gauge-Higgs Grand Unification

TL;DR

This paper develops a realistic $SO(11)$ gauge-Higgs grand unification model in warped space, demonstrating dynamical electroweak symmetry breaking, fermion mass generation, and proton stability, while noting a discrepancy in the Higgs mass prediction.

Contribution

It presents a comprehensive $SO(11)$ gauge-Higgs grand unification model with realistic fermion masses and symmetry breaking mechanisms in warped space, addressing proton decay and exotic fermions.

Findings

Electroweak symmetry is dynamically broken to $U(1)_{EM}$.

Fermion masses are generated via Hosotani mechanism and brane interactions.

Predicted Higgs mass is smaller than observed.

Abstract

The $SO(11)$ gauge-Higgs grand unification in the Randall-Sundrum warped space is presented. The 4D Higgs field is identified as the zero mode of the fifth dimensional component of the gauge potentials, or as the fluctuation mode of the Aharonov-Bohm phase $\theta_H$ along the fifth dimension. Fermions are introduced in the bulk in the spinor and vector representations of $SO(11)$. $SO(11)$ is broken to $SO(4) \times SO(6)$ by the orbifold boundary conditions, which is broken to $SU(2)_L \times U(1)_Y \times SU(3)_C$ by a brane scalar. Evaluating the effective potential $V_{\rm eff} (\theta_H)$, we show that the electroweak symmetry is dynamically broken to $U(1)_{\rm EM}$. The quark-lepton masses are generated by the Hosotani mechanism and brane interactions, with which the observed mass spectrum is reproduced. The proton decay is forbidden thanks to the new fermion number conservation. It is pointed out that there appear light exotic fermions. The Higgs boson mass is determined with the quark-lepton masses given, which, however, turns out smaller than the observed value.