Gauge Model with Hypermultiplets in Harmonic Superspace

We provide a manifestly N = 2 supersymmetric formulation of the N = 2 U(Nc) gauge model constructed in terms of N = 1 superfields in hep-th/0409060. The model is composed of N = 2 vector multiplets in harmonic superspace and can be viewed as the N = 2 U(Nc) Yang-Mills effective action equipped with the electric and magnetic Fayet-Iliopoulos terms. We generalize this gauge model to an N = 2 U(Nc) QCD model by introducing N = 2 hypermultiplets in harmonic superspace which include both the fundamental representation of U(Nc) and the adjoint representation of U(Nc). The effect of the magnetic Fayet-Iliopoulos term is to shift the auxiliary field by an imaginary constant. Examining vacua of the model, we show that N = 2 supersymmetry is spontaneously broken down to N = 1. e-mail: [email protected] e-mail: [email protected] e-mail: makoto [email protected]