Bounds on masses of bulk fields in string compactifications

TL;DR

This paper argues that in string compactifications with low-energy supersymmetry, bulk fields typically have masses lighter than the inverse size of the compactification manifold, affecting mediation mechanisms.

Contribution

It provides a theoretical argument that generic string models with stabilized moduli feature light bulk fields, impacting supersymmetry breaking mediation scenarios.

Findings

Bulk fields are parametrically lighter than 1/R after moduli stabilization.

Light bulk states influence anomaly and gaugino mediation.

Implications for low-energy phenomenology in string models.

Abstract

In string compactification on a manifold X, in addition to the string scale and the normal scales of low-energy particle physics, there is a Kaluza-Klein scale 1/R associated with the size of X. We present an argument that generic string models with low-energy supersymmetry have, after moduli stabilization, bulk fields with masses which are parametrically lighter than 1/R. We discuss the implications of these light states for anomaly mediation and gaugino mediation scenarios.