Negative Pion Production from Neutrons by Polarized<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>γ</mml:mi></mml:math>Rays

Abstract

The differential asymmetry ratio for the process $\ensuremath{\gamma}+n\ensuremath{\rightarrow}p+{\ensuremath{\pi}}^{\ensuremath{-}}$ was measured at 90\ifmmode^\circ\else\textdegree\fi{} in the center-of-mass system and for incident photon energies from 352 to 550 MeV. The observed asymmetries are larger than the values predicted from the theory by Berends, Donnachie, and Weaver. A smaller ${M}_{1}$- amplitude gives better agreement between the experiment and the theory.