Is There Scale Invariance in N=1 Supersymmetric Field Theories ?

In two dimensions, it is well known that the scale invariance can be considered as conformal invariance. However, there is no solid proof of this equivalence in four or higher dimensions. We address this issue in the context of 4d $\mathcal{N}=1$ SUSY theories. The SUSY version of dilatation current for theories without conserved $R$ symmetry is constructed through the FZ-multiplet. We discover that the scale-invariant SUSY theory is also conformal when the real superfield in the dilatation current multiplet is conserved. Otherwise, it is only scale-invariant, despite of the transformation of improvement.