Noncommutative Standard Model : Model Building

A noncommutative version of the usual electro-weak theory is constructed. We discuss how to overcome the two major problems: 1) although we can have noncommuta-tive U (n) (which we denote by U ⋆ (n)) gauge theory we cannot have noncommutative SU (n) and 2) the charges in noncommutative QED are quantized to just 0, ±1. We show how the problem with charge quantization, as well as with the gauge group, can be resolved by taking U ⋆ (3) × U ⋆ (2) × U ⋆ (1) gauge group and reducing the extra U (1) factors in an appropriate way. Then we proceed with building the noncommutative version of the standard model by specifying the proper representations for the entire particle content of the theory, the gauge bosons, the fermions and Higgs. We also present the full action for the noncommutative Standard Model (NCSM). In addition, among several peculiar features of our model, we address the inherent CP violation and new neutrino interactions.