Isospin decomposition of the photoproduced Σπ system near the image

Recent experimental results for the reaction image from CLAS at Jefferson Lab are discussed. It was found that the mass distributions or “line shapes” of the three charge combinations image, image and image differ significantly. Our results show that the image, as the image constituent of the reaction, must be accompanied by an image component. We discuss phenomenological fits to the data to test the possible forms and magnitudes of these amplitudes. A two-amplitude image fit of Breit–Wigner form to the image channel alone works quite well. The addition of a single image amplitude works fairly well to model all the line shapes simultaneously.