Chew-Theory Approach to the Scattering of Low-EnergyK+Particles by Nucleons

Abstract

The method successfully used by Chew in the treatment of pion-nucleon scattering is applied to the scattering of ${K}^{+}$ mesons by nucleons. Two mechanisms are considered. In the first the $K$ mesons are emitted and absorbed directly by the nucleon or hyperon, and in the second the force is transmitted by the $\ensuremath{\pi}$-meson field in the manner proposed by Schwinger. Distinguishing characteristics of the two mechanisms are discussed and predictions concerning the angular distributions and isotopic spin dependence at energies less than 100 Mev are given. Some unusual features of the $\ensuremath{\pi}$-meson exchange mechanism connected with the $S\ensuremath{-}P$ wave coupling are noted. Within the framework of the general Chew-type approach, a predominant $\ensuremath{\pi}$-coupling mechanism appears incompatible with recent data. A direct emission absorption mechanism with ${\ensuremath{\gamma}}_{5}$ coupling and with the square of the $K\ensuremath{-}\ensuremath{\Lambda}$-nucleon coupling constant three times that of the $K\ensuremath{-}\ensuremath{\Sigma}$-nucleon coupling constant is suggested. The scattering obtained from this model using the Chew approach is considerably damped compared with the perturbation result. Correspondingly the coupling constant obtained from Chew theory is larger than that obtained from perturbation theory.