Effective Field Theory and the Signatures of New Physics

This thesis presents a variety of applications of effective field theory techniques to problems in particle phenomenology. Topics relating to the physics of the standard model and to some of its possible extensions are considered. Techniques from the heavy quark effective theory and effective chiral lagrangians are used to study the low-energy phenomenology of QCD, and to explore the consequences of strongly interacting physics that may lie beyond the standard model. A significant portion of this thesis focuses on the phenomenology of the simplest possible extension of the standard model, technicolor with a massless scalar doublet. By constructing the appropriate effective chiral lagrangian, it is shown that this model is consistent with the current experimental constraints. In addition, the most likely collider signatures are determined. Each of examples presented in this thesis demonstrates the power of effective field theory techniques in extracting useful information from a quantum field theory by focusing only on the physics that is essential at the energy scales of interest.