Anomalous Higgs interactions in gauge-Higgs unification

Abstract

We discuss anomalous Higgs interactions in the scenario of gauge-Higgs unification. In the scenario Higgs originates from higher dimensional gauge field and has a physical meaning as AB phase or Wilson loop. As its inevitable consequence, physical observables are expected to be periodic in the Higgs field. In particular, the Yukawa coupling is expected to show some periodic and non-linear behavior as the function of the Higgs VEV. For a specific choice of the VEV, the Yukawa coupling of KK zero mode fermion even vanishes. On the other hand, the Yukawa coupling is originally provided by gauge interaction, which is linear in the Higgs field. We discuss how such two apparent contradiction about the non-linearity of the Yukawa coupling can be reconciled and at the same time how these two "pictures" give different predictions in the simplest framework of the scenario: SU (3) electroweak model in 5-dimensional flat space-time with orbifolding. The deviation of the Yukawa coupling from the standard model prediction is also calculated for arbitrary VEV. We study "H-parity", which guarantees the stability of the Higgs for a specific choice of the VEV. Also discussed is the Higgs interaction with W ± and Z 0 . It turns out that in our framework of flat space-time the interaction does not show deviation from the standard model prediction, except for the specific case of the VEV.

Deviation of Yukawa coupling in gauge-Higgs unification

“…This fact is one of the characteristic features of GHU and the physical observables are expected to have the periodicity in the Higgs field. Actually, it has been already reported in [10] in the flat extra dimensional case and [11] in the warped extra dimensional case that Higgs coupling to the fermions have such a periodicity. In [10], the ratio of yukawa coupling of GHU and the SM one is derived as 4) which is quite distinctive from the other models beyond the SM.…”

“…Actually, it has been already reported in [10] in the flat extra dimensional case and [11] in the warped extra dimensional case that Higgs coupling to the fermions have such a periodicity. In [10], the ratio of yukawa coupling of GHU and the SM one is derived as 4) which is quite distinctive from the other models beyond the SM. In particular, as was pointed out in [10,11], the yukawa coupling vanishes at v = 1/(g 4 R) due to the periodicity.…”

“…In [10], the ratio of yukawa coupling of GHU and the SM one is derived as 4) which is quite distinctive from the other models beyond the SM. In particular, as was pointed out in [10,11], the yukawa coupling vanishes at v = 1/(g 4 R) due to the periodicity.…”

“…We study the deviations of Higgs coupling to fermions from the SM predictions by using a five dimensional GHU model of SU (3) gauge theory. Unlike the analysis where only the bulk Lagrangian was considered [10], we take into account the effects from the brane mass terms necessary in a more realistic model for generating the flavor mixing as clarified in [12] and removing the exotic massless fermions absent in the SM. The brane mass terms change the boundary conditions of mode equations, which give the formula to determine Kaluza-Klein (KK) mass spectrum m n (v).…”

Deviation of Yukawa Coupling and Higgs Decay in Gauge-Higgs Unification

“…The finiteness of other physical observables have been investigated [5][6][7] . The fact that the yukawa couplings are governed by the gauge principle may deviate from the SM one 8,9 . Actually, in the flat extra dimensional case, the ratio of yukawa coupling of GHU and the SM one is derived as…”