Probing the Delta NN component of He-3 - art. no. 044001

The He-3(gamma, pi(+/-)p) reactions were measured simultaneously over a tag ged photon energy range of 800 less than or equal to E gamma less than or e qual to 1120 MeV, well above the Delta resonance region. An analysis was pe rformed to kinematically isolate Delta knockout events from conventional De lta photoproduction events, and a statistically significant excess of pi(+) p events was identified, consistent with Delta(++) knockout. Two methods we re used to estimate the Delta NN probability in the He-3 ground state corre sponding to the observed knockout cross section. The first gave a lower pro bability limit of 1.5 +/- 0.6 +/- 0.5%; the second yielded an upper limit o f about 2.6%.