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

Abstract

Fermion pair production at e − e þ linear collider experiments with polarized e − and e þ beams is examined in the GUT inspired SOð5Þ × Uð1Þ × SUð3Þ gauge-Higgs unification. There arises large parity violation in the couplings of leptons and quarks to Kaluza-Klein (KK) excited neutral vector bosons Z 0 s, which leads to distinctive polarization dependence in cross sections, forward-backward asymmetries, leftright 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 þ linear collider experiments with energies 250 GeV to 1 TeV.

Signals of $W'$ and $Z'$ bosons at the LHC in the $SU(3) \times SO(5) \times U(1)$ gauge-Higgs unification

“…(1) R bosons are shown in Refs. [46,50]. The masses of W (1) , Z (1) and γ (1) bosons are almost degenerate and about 0.8 times the KK mass scale.…”

“…Hence physics of the Higgs boson is governed by the gauge principle and the Higgs boson mass is generated by quantum corrections in GHU models. Many GHU models are proposed for the electroweak unification [42][43][44][45][46][47][48][49][50][51][52][53][54][55] and GHU models for the grand unification are also presented [57][58][59][60][61][62][63][64]. Among them two types of SU (3) C ×SO( 5)×U (1) X GHU models in the warped spacetime have been studied.…”

“…One of them is called the "Amodel", where quark-lepton multiplets are introduced in the vector representation of SO(5) [42][43][44][45][46]. The other is called the "B-model", where quark-lepton multiplets are introduced in the spinor representation of SO(5) [47][48][49][50][51] which has been motivated from the study of the SO (11) gauge-Higgs GUT [57][58][59][60], and is called the GUT inspired GHU model.…”

“…The effects of Z bosons in the GHU B-model at the ILC have been studied in Ref. [50]. The deviation of the forward-backward asymmetry from the SM prediction is about −1% in the e + e − → µ + µ − process at the 250 GeV ILC with polarized left-handed electron beams for θ H 0.10, where the KK mass scale is 13…”

Top and heavy quark studies at linear colliders

“…On the other hand Ref. [15] underlines for models based on Grand Higgs Unification a) that deviations from the Standard Model are already measurable at √ 𝑠 = 250 GeV,…”