Moduli Stabilization in Chiral Type IIB Orientifold Models with Fluxes

We consider Type IIB orientifold models on Calabi-Yau spaces with three-form G-flux turned on. These fluxes freeze some of the complex structure moduli and the complex dilaton via an F-term scalar potential. By introducing pairs of D9-D9 branes with abelian magnetic fluxes it is possible to freeze also some of the Kähler moduli via a D-term potential. Moreover, such magnetic fluxes in general lead to chiral fermions, which make them interesting for string model-building. These issues are demonstrated in a simple toy model based on a ZZ2 × ZZ2 orbifold. On sabbatical leave from Department of Physics, Northeastern University, Boston, MA 02115, USA.