Asymmetries in Charged-Pion Photoproduction on Nucleons by 16-GeV Polarized Photons

Abstract

Asymmetries in charged-pion photoproduction from hydrogen and deuterium have been measured with 16-GeV linearly polarized photons. Considerable energy dependence is seen in the natural-parity contribution to the $\frac{{\ensuremath{\pi}}^{\ensuremath{-}}}{{\ensuremath{\pi}}^{+}}$ ratio from deuterium, and in the unnatural-parity part of the cross section for $\ensuremath{\gamma}n\ensuremath{\rightarrow}{\ensuremath{\pi}}^{\ensuremath{-}}p$. The energy dependence of this latter cross section is consistent with the expected from a conventional pion Regge trajectory.