LHC signals of the SO(5)×U(1) gauge-Higgs unification

Department of Physics, Osaka University, 1-1 Toyonaka, 560-0043 Osaka, Japan

^a e-mail: shimon@het.phys.sci.osaka-u.ac.jp

Published online: 29 May 2015

Abstract

We study the LHC signals of SO(5)×U(1) gauge-Higgs unification as a beyond the standard model (SM). When the extra dimensional space is not simply-connected, dynamics of the Aharonov-Bohm (AB) phase, θ_H, in the extra dimension can induce dynamical gauge symmetry breaking by the Hosotani mechanism. The Kaluza-Klein (KK) mass spectra of γ, Z, Z_R and Higgs self couplings obey universal relations with θ_H in the fifth dimension. In our model, three neutral gauge bosons, Z′ bosons, appear at TeV scale. Z′ bosons are the first KK modes Z_R⁽¹⁾, Z⁽¹⁾, and γ⁽¹⁾. We analyze Z′ bosons through dilepton events at LHC. For θ_H = 0.114, the mass and decay width of Z_R⁽¹⁾, Z⁽¹⁾, and γ⁽¹⁾ are (5.73, 482), (6.07, 342), and (6.08 TeV, 886 GeV), respectively. For θ_H = 0.073 their masses are 8.00 ∼ 8.61 TeV. An excess of events in the dilepton invariant mass should be observed in the Z′ search at the upgraded LHC at 14 TeV.