Evidence for narrow Delta(0)(1232) states in the C-12(e, e ' p pi(-))C-11 Reaction

The reaction C-12(e,e'Delta(0))C-11 --> C-12(e,e'p pi(-))C-11 was investiga ted at the Mainz Microtron MAMI in a triple coincidence measurement using t he three spectrometer setup of the Al Collaboration. The good missing mass resolution of sigma(m) = 0.27 MeV/c(2) allowed to select the events belongi ng to the ground state of 11C. Cutting on these events the excitation energ y spectra of C-12(Delta 0) show evidence for two peaks of about 4 MeV width (FWHM) at 282 MeV and 296 MeV with a significance of about 4.5 standard de viations. The peaks are interpreted in a simple weak coupling model as boun d Delta(0) states in C-12(Delta 0).