Recent Applications of KN Forward Dispersion Relations and Sum Rules

Abstract

Recent applications of kaon‐nucleon forward dispersion relations, superconvergence relations, finite energy sum rules, derivative sum rules, and the Adler‐Weisberger sum rule are reviewed. These dispersion relations and sum rules have been used for the determination of the KNA and KN coupling constants, the phases of the kaon‐nucleon forward scattering amplitudes, and the Regge pole parameters, and have allowed tests of the PCAC hypothesis for strangeness‐changing currents. They also provide important constraints which help to resolve ambiguities in the phenomenological analysis of the scattering data. A critical comparison of various methods which have been proposed is given, the theoretical predictions are compared with experiment when possible, and our present knowledge of the kaon‐nucleon interaction parameters is summarized. Some new results are presented.