An Exponentially Small $\mu$--term in String Theory

TL;DR

This paper presents a mechanism in string theory that generates an exponentially small $$-term on D5 branes via brane instanton effects, calculated through a geometric transition in a singularity.

Contribution

It introduces a novel method to produce a tiny $$-term in string theory using brane instantons and geometric transitions, expanding understanding of moduli stabilization.

Findings

Exponential suppression of the $$-term achieved.

Calculation of instanton effects via geometric transition.

Application to D5 branes on a deformed $A_3$ singularity.

Abstract

We describe a mechanism that produces an exponentially small $\mu$--term on the world--volumes of D5 branes wrapping a deformed and fibered $A_3$ singularity. The small $\mu$ arises due to brane instanton effects which can be calculated after a geometric transition at one of the nodes of the singularity.