Effective Field Theories for Low Energy Physics.

The effective field theory formalism is reviewed and applied to several diverse problems in modern particle physics. Heavy particle corrections to the weak interaction's (rho) parameter are calculated and constraints are placed on the existence of heavy particles. The weak radiative decays of the Hyperons are discussed using an effective chiral lagrangian. The renormalization group equations for the chiral quark model are derived and used to explain the (DELTA)I = 1/2 rule. Finally, some effects of adding a scalar field which possesses nontopological solitons to the standard model are examined.