π−pCharge-Exchange Differential Cross Section and Polarization in a Regge-Pole Model

Abstract

Regge-pole fits to ${\ensuremath{\pi}}^{\ensuremath{-}}p$ charge-exchange differential-cross-section and polarization data have been given at moderately high energies and over a wide range of momentum transfers. Besides the $\ensuremath{\rho}$ trajectory, whose slope and intercept are determined by exchange degeneracy, a conspiring ${\ensuremath{\rho}}^{\ensuremath{'}}$ trajectory of the same slope but intercept near zero has been taken into account. In the spirit of the Veneziano formula, the residues are assumed to be of the form $\frac{\mathrm{const}}{\ensuremath{\Gamma}(\ensuremath{\alpha})}$. A four-parameter fit gives good agreement with the experimental data.