CP, charge fractionalizations and low-energy effective actions in the SU(2) Seiberg-Witten theories with quarks

Several dynamical aspects of the SU(2) Seiberg-Witten models with Nf quark hypermultiplets are explored. We first clarify the meaning of the number of the singularities of the space of vacua. CP properties of the theories are then studied and periodicity of theories in θ with and without bare quark masses is obtained ((4- N_f) π and π respectively). CP noninvariance at a generic point of QMS manifests itself as the electric and quark-number charge fractionalizations for the dyons; we show that the exact Seiberg-Witten solution contains such effects correctly, in agreement with the semiclassical analysis recently made by F. Ferrari. Upon N = 1 perturbation the low-energy effective theories at the singularities display confinement, and in most cases chiral symmetry breaking as a consequence. In one of the vacua for N_f = 3 confinement is not accompanied by chiral symmetry breaking: we interpret it as an example of oblique confinement of 't Hooft. We discuss further the consistency of the physical picture found here by studying the effects of soft supersymmetry breaking as well as the behavior of the theory in the N = 1 limit.