## Physics Department Faculty Publication Series

1995

#### Abstract

I describe the methodology for the use of dispersion relations in connection with chiral perturbation theory. The conditions for matching the two formalisms are given at $O(E^2)$ and $O(E^4)$. The two have several complementary features, as well as some limitations, and these are described by the use of examples, which include chiral sum rules related to the Weinberg sum rules, form factors, and a more complicated reaction, $\gamma \gamma \rightarrow \pi \pi$.