Single Higgs boson production at electron-positron colliders in gauge-Higgs unification

We examine contributions to single Higgs boson production processes via Z' and W' bosons in the SU(3)C x SO(5)W x U(1)X gauge-Higgs unification (GHU) model. In particular, we analyze the cross sections of three single Higgs boson production processes e-e+ -Zh, e-e+ -nu nu over bar h, and e-e+ -e-e+h in the SM and the GHU model. For the Higgs strahlung process e-e+ -Zh, we show that for a parameter region satisfying the current experimental constraints, a maximum deviation from the SM is about up to 6% ffiffifor the center-of-mass energy of the initial electron and positron p = 250 GeV and that from the SM is s ffiffiabout up to 20% for p s = 500 GeV, depending on the initial ffiffipolarization of electron and positron. The deviation from the SM is monotonically increasing with respect to pfor ffisffi s p less than or similar to 1 TeV. By using the Higgs strahlung process, it is possible to explore up to the region of tens of TeV in terms of the Kaluza-Klein (KK) mass. We also show that the sign of the bulk mass of a lepton multiplet in the GHU model can be determined by examining the deviation of the left-right symmetry of the e-e+ -Zh process from the SM. The contributions to the cross sections of the e-e+ -nu nu over bar h and e-e+ -e-e+h processes via the Z' and W' bosons are relatively small compared to that for e-e+- Zhat least for pffisffi <= 1 TeV. As is the same as in the SM, the e-e+ -nu nu over bar h process gives a main contribution to the single Higgs boson production processes ffiffiforps greater than or similar to 500 GeV, but large deviations from the SM are only observed on energy scales close to the masses of the first KK gauge bosons or higher.

Automated summary

In this paper, we studied the contributions to single Higgs boson production processes via Z' and W' bosons in the GHU model. We analyzed the cross sections of three processes and found that the deviation from the SM increases with respect to the center-of-mass energy and can reach up to 20% for certain energy scales. We also showed that the sign of the bulk mass of a lepton multiplet in the GHU model can be determined by examining the deviation of the left-right symmetry.