Study of the Absorption Model in Pion-Nucleon Charge-Exchange Scattering

Abstract

The predictions of a peripheral $\ensuremath{\rho}$-exchange model with absorption are studied for the ${\ensuremath{\pi}}^{\ensuremath{-}}p$ charge-exchange reaction. Comparisons with experiment of predicted differential cross sections are made at laboratory momenta of 5.9 and 10.0 $\frac{\mathrm{BeV}}{c}$. It is found that absorption parameters determined from pion-nucleon elastic-scattering data fail to provide a fit to the angular distribution, absolute magnitude, or energy dependence of the observed cross sections. Even the assumption of essentially complete absorption of low partial waves still fails to fit absolute magnitudes and energy dependence, but it can give an acceptable angular dependence if the anomalous magnetic coupling of the $\ensuremath{\rho}$ is neglected. It is concluded that the simple absorption model is not an adequate representation of the experimental situation. Implications and possible modifications of the theory are discussed.