Moduli stabilization in type IIB orientifolds (II)

We discuss general properties of moduli stabilization in KKLT scenarios in type IIB orientifold compactifications X-6. In particular, we find conditions for the Kahler potential to allow a KKLT scenario for a manifold X-6 without complex structure moduli, i.e. h((2.1))((-)) (X-6) = 0. This way, a whole class of type IIB orientifolds with h((2.1))((-))(X-6) = 0 is ruled out. This excludes in particular all Z(N)- and Z(N) x Z(M)-orientifolds X-6 with h((2, 1))(X-6) = 0 for a KKLT scenario. This concerns Z(3), Z(7), Z(3) x Z(3), Z(4) x Z(4), Z(6) x Z(6) and Z(2) x Z(6')-both at the orbifold point and away from it. Furthermore, we propose a mechanism to stabilize the Kahler moduli associated to the odd cohomology H--((1.1)) (X-6). In the second part of this work we discuss the moduli stabilization of resolved type IIB Z(N)- or Z(N) x Z(M)-orbifold/orientifold compactifications. As examples for the resolved Z(6) and Z(2) x Z(4) orbifolds we fix all moduli through a combination of fluxes and racetrack superpotential. (C) 2006 Elsevier B.V. All rights reserved.