SUSY breaking mediation by D-brane instantons

TL;DR

This paper explores how D-brane instantons in string theory can mediate supersymmetry breaking effects between hidden and visible sectors, generating soft terms and providing a string-theoretic realization of a Polonyi model.

Contribution

It extends the understanding of D-brane instantons to supersymmetry breaking scenarios, introducing instanton mediation and illustrating it with Type IIB orientifolds.

Findings

D-brane instantons can generate perturbatively forbidden soft terms.

A string theory realization of a Polonyi hidden sector is provided.

The mechanism offers a new way to mediate SUSY breaking in string models.

Abstract

It is well known that D-brane instantons can generate contributions to the effective superpotential of gauge theories living on D-branes which are perturbatively forbidden by global U(1) symmetries. We extend this idea to theories with supersymmetry breaking, studying the effect of D-brane instantons stretched between the SUSY-breaking and visible sectors. Analogously to what happens in the SUSY case, this mechanism can give rise to perturbatively forbidden soft terms (among other effects). We introduce and discuss general properties of instanton mediation. We illustrate our ideas in simple Type IIB toroidal orientifolds. As a bi-product, we present a string theory realization of a Polonyi hidden sector.