Explicit Supersymmetry Breaking on Boundaries of Warped Extra Dimensions

TL;DR

This paper investigates the challenges and possibilities of explicitly breaking supersymmetry on boundaries in warped extra-dimensional theories, highlighting differences from flat space and exploring phenomenological implications.

Contribution

It demonstrates that complete supersymmetry breaking by boundaries is inconsistent with supergravity in warped spaces and explores low-energy models with boundary breaking.

Findings

Complete boundary supersymmetry breaking is inconsistent with supergravity in warped space.

Low-energy effective theories can be consistent when gravity is decoupled.

Warped models can achieve gauge coupling unification similar to MSSM.

Abstract

Explicit supersymmetry breaking is studied in higher dimensional theories by having boundaries respect only a subgroup of the bulk symmetry. If the boundary symmetry is the maximal subgroup allowed by the boundary conditions imposed on the fields, then the symmetry can be consistently gauged; otherwise gauging leads to an inconsistent theory. In a warped fifth dimension, an explicit breaking of all bulk supersymmetries by the boundaries is found to be inconsistent with gauging; unlike the case of flat 5D, complete supersymmetry breaking by boundary conditions is not consistent with supergravity. Despite this result, the low energy effective theory resulting from boundary supersymmetry breaking becomes consistent in the limit where gravity decouples, and such models are explored in the hope that some way of successfully incorporating gravity can be found. A warped constrained standard model leads to a theory with one Higgs boson with mass expected close to the experimental limit. A unified theory in a warped fifth dimension is studied with boundary breaking of both SU(5) gauge symmetry and supersymmetry. The usual supersymmetric prediction for gauge coupling unification holds even though the TeV spectrum is quite unlike the MSSM. Such a theory may unify matter and Higgs in the same SU(5) hypermultiplet.