Off-Shell Extended Supersymmetries and Lorentz-Violating Abelian Gauge Models

In this work, we propose the N=2 and N=4 supersymmetric extensions realized off-shell of the Abelian gauge model with Chern-Simons Lorentz-breaking term. We start with the theory in 6 and 10 dimensions and reduce \`{a} la Scherk the space-like coordinates to carry out the D=5 model in both cases. Then, we reduce the fifth space-like coordinate using the Legendre transformation technique for dimensional reduction. The last reduction method provides us with auxiliary fields that yield the superalgebra closed off-shell. Since the reduced bosonic Lagrangians from $6D$ and $10D$ are the same as the N=2 and N=4 SUSY-versions of the theory, respectively, we use the superspace-superfield formalism in N=1 to achieve the supersymmetric version of model.