Dilaton supersymmetry breaking

We argue that dilaton supersymmetry breaking in string derived supergravity requires an effective superpotential which is not separable as a function of the dilaton times a function of the moduli. We show that in a simple model with hidden sector matter condensation and a dilaton independent term one can easily obtain |FS| ≠= 0. For a wide range of realistic model parameters |FS| ⪢ |FT| and supersymmetry is mainly broken in the dilaton direction.