The Little Hierarchy in Universal Extra Dimensions

Abstract

In the standard model in universal extra dimensions (UED) the mass of the Higgs field is driven to the cutoff of the higher-dimensional theory. This re-introduces a small hierarchy since the compactification scale 1/R should not be smaller than the weak scale. In this paper we study possible solutions to this problem by considering five-dimensional theories where the Higgs field potential vanishes at tree level due to a global symmetry. We consider two avenues: a Little Higgs model and a Twin Higgs model. An obstacle for the embedding of these four-dimensional models in five dimensions is that their logarithmic sensitivity to the cutoff will result in linear divergences in the higher dimensional theory. We show that, despite the increased cutoff sensitivity of higher dimensional theories, it is possible to control the Higgs mass in these two scenarios. For the Little Higgs model studied, the phenomenology will be significantly different from the case of the standard model in UED. This is due to the fact that the compactification scale approximately coincides with the scale where the masses of the new states appear. For the case of the Twin Higgs model, the compactification scale may be considerably lower than the scale where the new states appear. If it is as low as allowed by current limits, it would be possible to experimentally observe the standard model Kaluza-Klein states as well as a new heavy quark. On the other hand, if the compactification scale is higher, then the phenomenology at colliders would coincide with the one for the standard model in UED.

25 pages, 2 figures

References in corpus (24)

• The Cosmological Parameters 2006
• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• Bounds on Universal Extra Dimensions
• The Littlest Higgs
• The Twin Higgs: Natural Electroweak Breaking from Mirror Symmetry
• The Minimal Moose for a Little Higgs
• Little Higgs Review
• Radiative Corrections to Kaluza-Klein Masses
• Little Higgs Models and Their Phenomenology
• $\mbox{SU}(3)_L \otimes \mbox{U}(1)_N$ and $\mbox{SU}(4)_L \otimes \mbox{U}(1)_N$ gauge models with right-handed neutrinos
• Bosonic Supersymmetry? Getting Fooled at the LHC
• Neutral Currents and GIM Mechanism in SU(3)_L X U(1)_N Models for Electroweak Interactions
• The Little Higgs from a Simple Group
• Discrimination of Supersymmetry and Universal Extra Dimensions at Hadron Colliders
• A Twin Higgs Model from Left-Right Symmetry
• Natural Little Hierarchy from a Partially Goldstone Twin Higgs
• The Simplest Little Higgs
• Number of Fermion Generations Derived from Anomaly Cancellation
• Resonances from Two Universal Extra Dimensions
• Mirror World at the Large Hadron Collider
• Six-Dimensional Gauge Theory on the Chiral Square
• Neutrinos Vis-a-vis the Six-Dimensional Standard Model
• Little Higgs Models and Electroweak Measurements
• S, T, U parameters in $SU(3{)}_C\times SU(3{)}_L\times U(1)$ model with right-handed neutrinos

Cited by in corpus (11)

• Dark Matter and Collider Phenomenology of Universal Extra Dimensions
• KK Parity in Warped Extra Dimension
• Leptons and photons at the LHC: cascades through spinless adjoints
• Cheng-Weyl Vector Field and its Cosmological Application
• A Little Twin Higgs Model
• Bounds on the Simplest Little Higgs Model Mass Spectrum Through Z Leptonic Decay
• Status Report on Universal Extra Dimensions After LHC8
• The Size of Compact Extra Dimensions from Blackbody Radiation Laws
• Two Universal Extra Dimensions
• Review of Neutral Naturalness
• A Mechanism for Kaluza-Klein Number Violation in UED and Implications for LHC