Moduli Stabilization and Supersymmetry Breaking in Effective Theories of Strings

In the “central” region of moduli space of string theories, which is most likely to describe the “real world,” the string coupling is about unity and the volume of compact dimensions is about the string volume. We map this region, assuming that the string coupling and compact volume moduli are chiral superfields of N = 1 supergravity in four dimensions, and requiring that the supersymmetry (SUSY) breaking scale is about the weak scale and that the cosmological constant be acceptably small. We find that the SUSY breaking field has a weak scale mass and a flat potential, that the potential is steep in other directions, and that there are additional nearby minima with a large negative cosmological constant.