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Finite Radiative Electroweak Symmetry Breaking from the Bulk

Nima Arkani-Hamed, Lawrence Hall, Yasunori Nomura, David Smith, Neal Weiner

TL;DR

The paper introduces a novel radiative mechanism for electroweak symmetry breaking in a five-dimensional supersymmetric framework where a TeV-scale compact dimension sets the EWSB scale via $1/R$. By localizing the top Yukawa coupling on a Yukawa brane and breaking supersymmetry away in the bulk, the Higgs mass-squared receives a finite, negative radiative correction dominated by top-quark KK propagation across the bulk, with the quadratic divergence effectively cut off at the scale $D \sim R$. The resulting Higgs mass is naturally lighter than the KK and superpartner spectrum ($m_H \sim 0.2/R$) and largely insensitive to ultraviolet details, enabling $R^{-1}$ in the 2–3 TeV range. The authors provide explicit models with local and non-local SUSY breaking, compute the KK spectra and the radiatively induced $m_{H_u}^2$, and discuss phenomenology including LSP nature and distinctive collider signatures such as highly ionizing tracks and events with two Higgs bosons plus missing energy. This framework links EWSB to the geometry of extra dimensions and offers concrete, testable predictions at TeV-scale colliders.

Abstract

A new physical origin for electroweak symmetry breaking is proposed, involving compact spatial dimensions of scale 1/R \approx 1 TeV. The higher dimensional theory is supersymmetric, and hence requires the top-quark Yukawa coupling to be localized on some ``Yukawa brane'' in the bulk. The short distance divergence in the Higgs-boson mass is regulated because supersymmetry is unbroken in the vicinity of this Yukawa brane. A finite, negative Higgs mass-squared is generated radiatively by the top-quark supermultiplet propagating a distance of order R from the Yukawa brane to probe supersymmetry breaking. The physics of electroweak symmetry breaking is therefore closely related to this top propagation across the bulk, and is dominated by the mass scale 1/R, with exponential insensitivity to higher energy scales. The masses of the superpartners and the Kaluza-Klein resonances are also set by the mass scale 1/R, which is naturally larger than the W boson mass by a loop factor. Explicit models are constructed which are highly constrained and predictive. The finite radiative correction to the Higgs mass is computed, and the Higgs sector briefly explored. The superpartner and Kaluza-Klein resonance spectra are calculated, and the problem of flavor violation from squark and slepton exchange is solved. Important collider signatures include highly ionizing charged tracks from stable top squarks, and events with two Higgs bosons and missing transverse energy.

Finite Radiative Electroweak Symmetry Breaking from the Bulk

TL;DR

The paper introduces a novel radiative mechanism for electroweak symmetry breaking in a five-dimensional supersymmetric framework where a TeV-scale compact dimension sets the EWSB scale via . By localizing the top Yukawa coupling on a Yukawa brane and breaking supersymmetry away in the bulk, the Higgs mass-squared receives a finite, negative radiative correction dominated by top-quark KK propagation across the bulk, with the quadratic divergence effectively cut off at the scale . The resulting Higgs mass is naturally lighter than the KK and superpartner spectrum () and largely insensitive to ultraviolet details, enabling in the 2–3 TeV range. The authors provide explicit models with local and non-local SUSY breaking, compute the KK spectra and the radiatively induced , and discuss phenomenology including LSP nature and distinctive collider signatures such as highly ionizing tracks and events with two Higgs bosons plus missing energy. This framework links EWSB to the geometry of extra dimensions and offers concrete, testable predictions at TeV-scale colliders.

Abstract

A new physical origin for electroweak symmetry breaking is proposed, involving compact spatial dimensions of scale 1/R \approx 1 TeV. The higher dimensional theory is supersymmetric, and hence requires the top-quark Yukawa coupling to be localized on some ``Yukawa brane'' in the bulk. The short distance divergence in the Higgs-boson mass is regulated because supersymmetry is unbroken in the vicinity of this Yukawa brane. A finite, negative Higgs mass-squared is generated radiatively by the top-quark supermultiplet propagating a distance of order R from the Yukawa brane to probe supersymmetry breaking. The physics of electroweak symmetry breaking is therefore closely related to this top propagation across the bulk, and is dominated by the mass scale 1/R, with exponential insensitivity to higher energy scales. The masses of the superpartners and the Kaluza-Klein resonances are also set by the mass scale 1/R, which is naturally larger than the W boson mass by a loop factor. Explicit models are constructed which are highly constrained and predictive. The finite radiative correction to the Higgs mass is computed, and the Higgs sector briefly explored. The superpartner and Kaluza-Klein resonance spectra are calculated, and the problem of flavor violation from squark and slepton exchange is solved. Important collider signatures include highly ionizing charged tracks from stable top squarks, and events with two Higgs bosons and missing transverse energy.

Paper Structure

This paper contains 8 sections, 40 equations, 3 figures.

Table of Contents

  1. Introduction
  2. Radiative Correction to the Higgs-Boson Mass
  3. Framework
  4. Calculation of the Higgs mass-squared
  5. Model with Localized Supersymmetry Breaking
  6. Setup
  7. Particle spectrum and radiatively induced $m_{H_u}^2$
  8. 5d interpretation

Figures (3)

  • Figure 1: One-loop diagrams contributing to the Higgs-boson mass.
  • Figure 2: Mass spectrum for the lowest KK modes of the bulk fields in our model, in the limit of very strong supersymmetry breaking, $\sqrt{F_Z} \gg M_* \gg M_c$. The fermion modes $\psi_n$ and $\psi^c_n$ form a Dirac state for $n>0$, while the modes of ${\lambda_1}$ and ${\lambda_2}$ combine to form nearly degenerate pairs of Majorana states.
  • Figure :