Dimensional regularization and supersymmetry

The techniques of supersymmetric dimensional regularization are examined in detail. A peculiar complementarity is found to be inherent in the regularization: its manifestly supersymmetric version is contradictory, while the removal of inconsistencies costs a loss of supersymmetry in higher orders. This phenomenon is analysed at the level of Feynman diagrams and an explicit example of supersymmetry breakdown in the three-loop approximation is discovered. In the light of this result the status of dimensional regularization in globally supersymmetric gauge theories are reconsidered