Exclusive 16O(γ,π-p) reaction in the Δ resonance region

We report the first exclusive ({gamma},{pi}{sup {minus}}{ital p}) measurements on a complex nucleus. The {sup 16}O({gamma},{pi}{sup {minus}}{ital p}) reaction was measured at pion laboratory angles of 64{degree} and 120{degree}. Coincident protons were detected over the quasifree angular correlation range using a vertical array of seven plastic scintillator detectors spanning {plus minus}33{degree} about the scattering plane. The cross sections are compared to factorized distorted-wave impulse approximation calculations; these provide a good description of the backward angle data, but are in serious disagreement with the forward angle data.