Small Extra Dimensions from the Interplay of Gauge and Supersymmetry Breaking

TL;DR

This paper explores how the interplay between gauge symmetry breaking and supersymmetry breaking in higher-dimensional models can naturally stabilize small extra dimensions, with a specific SO(10) orbifold model as illustration.

Contribution

It introduces a mechanism where Fayet-Iliopoulos terms and supersymmetry breaking work together to fix the size of extra dimensions at a small scale.

Findings

Compactification leads to additional U(1) symmetries.

Fayet-Iliopoulos terms fix gauge symmetry breaking scale.

Mechanism stabilizes extra dimensions at a small size.

Abstract

Higher-dimensional theories provide a promising framework for unified extensions of the supersymmetric standard model. Compactifications to four dimensions often lead to U(1) symmetries beyond the standard model gauge group, whose breaking scale is classically undetermined. Without supersymmetry breaking, this is also the case for the size of the compact dimensions. Fayet-Iliopoulos terms generically fix the scale M of gauge symmetry breaking. The interplay with supersymmetry breaking can then stabilize the compact dimensions at a size 1/M, much smaller than the inverse supersymmetry breaking scale 1/mu. We illustrate this mechanism with an SO(10) model in six dimensions, compactified on an orbifold.