Spontaneous symmetry breaking in nonlinear realization

Abstract

The symmetry properties of the $\pi$-N system are examined. It is shown that the nonlinearly realized SSB mechanism is proper for the effective theory of composite particles in low energy. Gauge particles in the nonlinear realization are Goldstone ones. The nonlinear realization is a manifestation of the spontaneously broken symmetry. The nonlinear realization itself and nonlinearly realized SSB mechanism are generally described. And, as an application, a Lagrangian with the nonlinear realization of the super-Poincare group is constructed. A massless Goldstone fermion appears as a result of the spontaneously broken supersymmetry.