Forward\u2013backward asymmetry in the gauge-Higgs unification at the International Linear Collider

Shuichiro Funatsu

doi:10.1140/epjc/s10052-019-7375-2

Abstract

The signals of the SO(5)times U(1) gauge-Higgs unification model at the International Linear Collider are studied. In this model, Kaluza–Klein modes of the neutral gauge bosons affect fermion pair productions. The deviations of the forward–backward asymmetries of the e^+e^-rightarrow bar{b}b, bar{t}t processes from the standard model predictions are clearly seen by using polarised beams. The deviations of these values are predicted for two cases, the bulk mass parameters of quarks are positive and negative case.

Highlights

After the discovery of the Higgs boson, search for new physics in the electroweak sector is one of the most important topics of the particle physics
New physics at the International Linear Collider (ILC) are predicted by many alternative models such as the Higgs portal dark matter models [5,6,7], two-Higgs doublet models [8,9,10], Georgi–Machacek model [11], supersymmetric models [12,13,14,15], littlest Higgs model [16,17], universal extra dimensional model [18], warped extra dimensional models [19,20,21], composite Higgs models [22,23,24] and other models [25]
In the S O(5) × U (1) gauge-Higgs unification (GHU) models, the Higgs boson mass is protected by the custodial symmetry and the

Summary

Introduction

After the discovery of the Higgs boson, search for new physics in the electroweak sector is one of the most important topics of the particle physics. From (13) and (14), it is straightforwardly derived that the product of the left- and right-handed fermion mode functions with the same KK number and the bulk mass, fL(n)(y) × f R(n)(y) is invariant under changing the sign of the bulk mass parameter c → −c. The Yukawa couplings and the fermion masses obtained from the Higgs boson vacuum expectation value are independent of the sign of the bulk mass parameters in the case that the left- and right-handed quarks have the same bulk mass. In this model, the above arguments are applicable. The left-handed third generation quarks couplings with Z bosons are large

Parameters

Couplings and decay widths

Cross section and forward–backward asymmetry

Findings

Summary