A Natural Mechanism for Supersymmetry Breaking with Zero Cosmological   Constant (Minor corrections of some formulae, no substantial change)
  Supersymmetric theories in four dimensions with chiral superfields have very rich BRS cohomology, which gives rise to potential anomalies in theories that contain composite antichiral spinor superfields. Assuming the coefficients are non-zero, absence of the anomalies would generate new constraints on theories. In addition, the anomalies give rise to a new kind of supersymmetry breaking which is quite different from the known kinds, and also naturally yields a zero cosmological constant after supersymmetry breaking. 
J. A. Dixon