Photoproduction of Charged Pions from Deuterium

Abstract

The photoproduction of charged pions from deuterium has been studied using a "monochromatic" gamma-ray beam of 292\ifmmode\pm\else\textpm\fi{}8 Mev. The energy spectra of both positive and negative pions at the laboratory angle of 120\ifmmode^\circ\else\textdegree\fi{} were determined and both agreed within experimental error with that predicted by the theory of Lax and Feshbach. The negative-to-positive ratio at 120\ifmmode^\circ\else\textdegree\fi{} was 1.07\ifmmode\pm\else\textpm\fi{}0.16, and within experimental error, was independent of meson energy. At an angle of 73\ifmmode^\circ\else\textdegree\fi{} the ratio was 0.90\ifmmode\pm\else\textpm\fi{}0.23 for 98.7 Mev mesons. The measured negative-to-positive ratio disagrees both with the simple classical picture of Brueckner and the phenomenological theory of Watson. Some results on the ratio using a bremsstrahlung beam are given.