Singularities, Gauge Dynamics, and Nonperturbative Superpotentials in String Theory

TL;DR

This paper explores how nonperturbative effects in certain string theory compactifications can destabilize supersymmetric vacua, leading to supersymmetry breaking, with explicit examples constructed via F-theory.

Contribution

It identifies specific nonperturbative superpotentials in 4d N=1 string compactifications and connects them to supersymmetry breaking mechanisms, providing explicit F-theory examples.

Findings

Destabilization of supersymmetric vacua by nonperturbative superpotentials.

Explicit F-theory constructions of models with dynamical superpotentials.

Potential link between tensionless strings and supersymmetry breaking.

Abstract

We describe a class of 4d N=1 compactifications of the $SO(32)$ heterotic/type I string theory which are destabilized by nonperturbatively generated superpotentials. In the type I description, the destabilizing superpotential is generated by a one instanton effect or gaugino condensation in a nonperturbative $SU(2)$ gauge group. The dual, heterotic description involves destabilization due to worldsheet instanton or $\it half$ worldsheet instanton effects in the two cases. A genericity argument suggests that a (global) supersymmetry-breaking model of Intriligator and Thomas might be typical in a class of string theory models. Our analysis also suggests that the tensionless strings which arise in the $E_8 \times E_8$ theory in six dimensions when an instanton shrinks to zero size should, in some cases, have supersymmetry breaking dynamics upon further compactification to four dimensions. We provide explicit examples, constructed using F-theory, of the two cases of dynamically generated superpotentials.