IMPLICATION OF DECOUPLING EFFECTS FOR ONE-LOOP CORRECTED EFFECTIVE ACTIONS FROM SUPERSTRING THEORY

We study the decoupling effects in one-loop corrected N = 1 supersymmetric theory with gauge neutral chiral superfields, by calculating the one-loop corrected effective Lagrangian that involves light and heavy fields with the mass scale M, and subsequently eliminating heavy fields by their equations of motion. In addition to new non-renormalizable couplings, we determine the terms that grow as log M. In a model derived from superstring theory, these terms can significantly modify low-energy predictions for the effective couplings of light fields. For example, in a class of heterotic superstring vacua with an anomalous U(1) the vacuum restabilization introduces such decoupling effects which in turn correct the low energy predictions for certain couplings by 10–50%.