Zero Mass Divergences in Expansions about Chiral and Scale Symmetry

摘要

Singularities of expansions in the symmetry breaking parameters of chiral and scale asymmetric theories are studied, in tree approximation, in polynomial Lagrangian models. The singularities are related;to the appearance of zero mass scalar fields, not necessarily Goldstone particles, at the radius of convergence of the expansion. Methods of avoiding these singularities are presented.