Near-threshold π^- photoproduction on the deuteron

The first experimental investigation of the near-threshold cross section for incoherent π^- photoproduction on the deuteron γ d -> π^- pp is presented. The experimental technique involved detection of the 131 MeV gamma ray resulting from the radiative capture of photoproduced π^- in the target. The total cross section has been measured using an unpolarized tagged-photon beam, a liquid-deuterium target, and three very large NaI(Tl) spectrometers. The data are compared to theoretical models that give insight into the elementary reaction γ n -> π^- p and pion-nucleon and nucleon-nucleon final-state interactions.