A new look at the nonlinear sigma model

Abstract

The study of the simplest case of effective field theory – the chiral SU(N) nonlinear sigma model will be presented. For last several decades it has played an extremely important role not only in the low energy phenomenology but also in many other areas of theoretical physics. It will be shown that the scattering amplitudes of n Goldstone bosons can be reconstructed using BCFW-like recursion relations. This method does not rely on the Lagrangian description and the only input is the four-point amplitudes together with the known analytic properties.