  The first experimental investigation of the near-threshold cross section for
incoherent $\pi^-$ photoproduction on the deuteron $\gamma$ d -> $\pi^-$ pp is
presented. The experimental technique involved detection of the ~131 MeV gamma
ray resulting from the radiative capture of photoproduced $\pi^-$ 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 $\gamma$ n -> $\pi^-$ p and pion-nucleon and
nucleon-nucleon final-state interactions.

Nuclear Experiment