Warped Supersymmetric Grand Unification

TL;DR

The paper presents a realistic SU(5) grand unified theory in a truncated AdS$_5$ spacetime where boundary conditions break the unified symmetry and the warp factor sets the electroweak scale via $T = k e^{-\,\pi k R}$. It shows that gauge coupling unification at leading-log is preserved, matching the MSSM prediction, while naturally achieving doublet-triplet splitting and proton decay suppression through boundary conditions and a bulk $U(1)_R$ symmetry. The model predicts a rich TeV-scale spectrum including XY gauge bosons/gauginos and colored Higgs states, with the lightest GUT particle (LGP) likely an XY gaugino that hadronizes into charged mesons, and a gravitino LSP of mass $\sim 10^{-3}$ eV. The authors also discuss a dual 4D AdS/CFT description in which a strong conformal sector yields the TeV-scale spectrum and SUSY breaking, while preserving low-energy gauge couplings in agreement with MSSM data. Phenomenologically, the framework offers distinctive collider signatures and provides a coherent picture linking Planck-scale unification with TeV-scale new physics.

Abstract

We construct a realistic theory of grand unification in AdS_5 truncated by branes, in which the unified gauge symmetry is broken by boundary conditions and the electroweak scale is generated by the AdS warp factor. We show that the theory preserves the successful gauge coupling unification of the 4D MSSM at leading-logarithmic level. Kaluza-Klein (KK) towers, including those of XY gauge and colored Higgs multiplets, appear at the TeV scale, while the extra dimension provides natural mechanisms for doublet-triplet splitting and proton decay suppression. In one possible scenario supersymmetry is strongly broken on the TeV brane, in which case the lightest SU(3)_C x SU(2)_L x U(1)_Y gauginos are approximately Dirac and the mass of the lightest XY gaugino is pushed well below that of the lowest gauge boson KK mode, improving the prospects for its production at the LHC. The bulk Lagrangian possesses a symmetry that we call GUT parity. If GUT parity is exact, the lightest GUT particle, most likely an XY gaugino, is stable. Once produced in a collider, the XY gaugino hadronizes to form mesons, some of which will be charged and visible as highly ionizing tracks. The lightest supersymmetric particle is the gravitino of mass \sim 10^{-3} eV, which is also stable if R parity is conserved.

Figures (3)

• Figure 1: One-loop corrections to the Planck correlator.
• Figure 2: A picture of the extra dimension.
• Figure 3: Scattering of two particles localized on the Planck brane.