Effects of Heavy States on the Effective N=1 Supersymmetric Action
  Using the power of superspace formalism, we investigate the decoupling effects of heavy states in N=1 supersymmetric field theory. We find that "mixed" couplings in the superpotential between the heavy and light fields contribute to the effective superpotential at the leading order, and also contribute to the effective K\"{a}hler potential (in the next to leading order). Mixed couplings in the K\"{a}hler potential always contribute to the effective K\"{a}hler potential at the leading order. Several examples are presented which illustrate the effects explicitly. 
Mirjam Cveti\v{c}, Lisa Everett, and Jing Wang