Limits on extra dimensions in orbifold compactifications of superstrings

TL;DR

This paper investigates how large extra dimensions, arising from supersymmetry breaking in string theories, could be detected through Kaluza-Klein excitations, providing bounds on their size within orbifold compactifications.

Contribution

It offers a model-independent analysis of Kaluza-Klein states in heterotic string orbifolds and computes limits on large extra dimensions related to supersymmetry breaking.

Findings

Constraints on the size of large extra dimensions

Characterization of Kaluza-Klein excitation signatures

Implications for future collider experiments

Abstract

Perturbative breaking of supersymmetry in four-dimensional string theories predict in general the existence of new large dimensions at the TeV scale. Such dimensions can be consistent with perturbative unification up to the Planck scale in a class of string models and open the exciting possibility of lowering a part of the massive string spectrum at energies accessible to future accelerators. The main signature is the production of Kaluza-Klein excitations which have a very particular structure, strongly correlated with the supersymmetry breaking mechanism. We present a model independent analysis of the physics of these states in the context of orbifold compactifications of the heterotic superstring. In particular, we compute the limits on the size of large dimensions used to break supersymmetry.