On soft SUSY breaking parameters in string models with anomalous U(1) symmetry

We study the magnitudes of soft SUSY breaking parameters in heterotic string models with anomalous U(1) symmetry. In most cases, D-term contribution to soft scalar masses is expected to be comparable to or dominant over other contributions provided that supersymmetry breaking is mediated by the gravitational interaction and/or an anomalous U(1) symmetry and the magnitude of vacuum energy is not more than of order $m_{3/2}^2 M^2$.