Supersymmetry breaking with zero vacuum energy in M-theory flux compactifications.

An attractive mechanism to break supersymmetry in vacua with zero vacuum energy arose in E(8) x E(8) heterotic models with hidden sector gaugino condensate. An H flux balances the exponentially small condensate on shell and fixes the complex structure moduli. At quantum level this balancing is, however, obstructed by the quantization of the H flux. We show that the warped flux compactification background in heterotic M theory can solve this problem through a warp-factor suppression of the integer flux relative to the condensate. We discuss the suppression mechanism both in the M theory and the four-dimensional effective theory and provide a derivation of the condensate's superpotential which is free of delta-function squared ambiguities.