In this work, we adopt the simplest model that spontaneously breaks
supersymmetry, namely, the minimal O'Raifeartaigh model. The effective
potential is computed in the framework of the linear delta expansion (LDE)
approach up to the order δ2, conjugated with superspace and supergraph
techniques. The latter can be duly mastered even if supersymmetry is no longer
exact and the efficacy of the superfield approach in connection with the LDE
procedure is confirmed according to our investigation. That opens up a way for
a semi-nonperturbative superspace computation which allows us to deal with
spontaneously broken supersymmetric models and encourages us to go further and
apply this treatment to the Minimal Supersymmetric Standard Model (MSSM)
precision tests.Comment: 42 pages, 22 figures, text modified, new paragraph added in the
conclusions, revtex