Non-Custodial Warped Extra Dimensions at the LHC?

TL;DR

This paper explores non-custodial warped extra dimension models with bulk Standard Model fields, analyzing their implications for Higgs measurements, electroweak precision tests, and potential signals at current and future colliders.

Contribution

It provides a detailed analysis of the phenomenology of non-custodial Randall-Sundrum models, including electroweak constraints and Yukawa coupling misalignments, with implications for collider detection.

Findings

Lower Kaluza-Klein gauge boson mass bounds to around 5 TeV.

Top Yukawa misalignment can reach 10%, observable at HL-LHC.

Corrections to bottom and tau Yukawas are at the percent level, detectable at future colliders.

Abstract

With the prospect of improved Higgs measurements at the LHC and at proposed future colliders such as ILC, CLIC and TLEP we study the non-custodial Randall-Sundrum model with bulk SM fields and compare brane and bulk Higgs scenarios. The latter bear resemblance to the well studied type III two-Higgs-doublet models. We compute the electroweak precision observables and argue that incalculable contributions to these, in the form of higher dimensional operators, could have an impact on the T-parameter. This could potentially reduce the bound on the lowest Kaluza-Klein gauge boson masses to the 5 TeV range, making them detectable at the LHC. In a second part, we compute the misalignment between fermion masses and Yukawa couplings caused by vector-like Kaluza-Klein fermions in this setup. The misalignment of the top Yukawa can easily reach 10%, making it observable at the high-luminosity LHC. Corrections to the bottom and tau Yukawa couplings can be at the percent level and detectable at ILC, CLIC or TLEP.