Alternative extension of supersymmetry

Alternative extensions of supersymmetry in higher dimensions are explored. A general Weyl-spinor-type extension is found that becomes just N=1 supersymmetry in 3+1 dimensions. In higher dimensions it can be broken to (N=1 supersymmetry) Ŝ (internal group), where the internal group can easily contain the standard model. Off-shell superspace actions are constructed. The flat-space generalization of the Wess-Zumino action is quantized and shown to be ultraviolet finite to all orders, when in higher dimensions. An off-shell superspace action for supergravity based on the alternative supersymmetry is given, and some prospects for quantization and dimensional reduction of this action are discussed.