Geometry and the Low-Energy Theorem in N=1 Supersymmetric Theories

Abstract

We investigate geometrical structures and low-energy theorems of N=1 supersymmetric nonlinear sigma models in four dimensions. When a global symmetry spontaneously breaks down to its subgroup, the low-energy effective Lagrangian of massless particles is described by a supersymmetric nonlinear sigma model whose target manifold is parametrized by Nambu-Goldstone (NG) bosons and quasi-NG (QNG) bosons. The unbroken symmetry changes at each point in the target manifold and some QNG bosons change to NG bosons when unbroken symmetry become smaller. The QNG-NG change and their interpretation is shown in a simple example, the O(N) model. We investigate low-energy theorems at general points.