Exchange-Degenerate Regge Trajectories and Meson-Nucleon Charge-Exchange Scattering

Based on exchange degeneracy and $\mathrm{SU}\left(3\right)\mathrm{}$ symmetry, a Regge-pole model fitting the differential cross sections for pion-nucleon and kaon-nucleon charge exchange and $\eta$ production as well as polarization in ${\pi }^{-}p\to {\pi }^{0}n$ is given. Besides the $\rho -A_2$ trajectory, a conspiring and exchange-degenerate ${\rho }^{\prime }-{A_2}^{\prime }$ trajectory with the same slope as $\rho -A_2$ but with an intercept near zero is taken into account. The residues are assumed to have $\frac{1}{\Gamma \left(\alpha \right)}$ behavior. A four-parameter fit gives good agreement with the experimental data.