Zero-Energy Intercepts of the $\rho$ and $R$ Trajectories, the $\mathrm{pn}$ Charge-Exchange Scattering, and the Difference in $\mathrm{pp}$ and $\mathrm{np}$ Total Cross Sections

It is shown that the existing high-energy data for the $\mathrm{np}$ charge-exchange differential cross section in the forward direction and the difference between $\mathrm{np}$ and $\mathrm{pp}$ total cross sections can be simulataneously explained in terms of two Regge trajectories. The two trajectories are the $\rho$ and the $R$ (using the notation of Pignotti in the preceding paper). The $R$ has parity and $G$ parity opposite to $\rho$ but the same isotopic spin. These two sets of quantum numbers in the crossed channel are the only possible ones with nonvanishing contribution to the processes in question. The conjecture of real analyticity of the generalized coupling constants, together with the existing data, requires the existence of an $R$ trajectory. In fitting the experimental data the intercepts are ${\alpha }_{\rho }\mathrm{}\left(0\right)=0.57\mathrm{}\pm 0.1$ and ${\alpha }_R\mathrm{}\left(0\right)=0.31\mathrm{}\pm 0.05$.