A New Mechanism of Kahler Moduli Stabilization in Type IIB Theory

We study the scalar potential in supersymmetric (orientifolded) Calabi Yau compactifications of Type IIB theory. We present a new mechanism to stabilize all closed string moduli at leading order in \alpha^{'} by introducing consistently fluxes. As usual we consider the dilaton and the complex structure moduli stabilized by turning on three-form fluxes that couple to the F-part of the scalar potential. Kahler moduli get fixed by the combined action of the flux-induced scalar masses with magnetic fields of the open string sector, and Fayet-Illiopoulos terms. For supersymmetric three-form fluxes the model is N=1, otherwise the mass terms are the scalar soft breaking terms of the SM fields. For the case of imaginary self dual three-form fluxes (ISD), the mass terms are positive and the minimum at the potential is at exactly zero energy. We argue that, under generic assumptions, this is a general mechanism for the full stabilization of closed string moduli. The vacua depend explicitly on the fluxes introduced in the manifold. A concrete realization of this mechanism on type IIB on a (T^ {6}/Z_{2}xZ_{2}) orientifold is provided.