Supersymmetric Nonlinear sigma Models Constrained on a Noncompact Manifold

摘要

Analysis by 1/n expansion of supersymmetric nonlinear sigma models in two dimensions with U(n) symmetry in which the scalar fields are constrained on a noncompact manifold is presented. The theories are ultraviolet finite. In the massless version of the models no mass scale is generated and gauge bosons fail to get dynamics while this is possible provided the theory contains a mass scale. The effects of introduction of the theta-term into supersymmetric theories are discussed. It is argued that supersymmetry is broken by the term only in finite supersymmetric theories. A singular behavior in the massless limit in these models is pointed out.