Short-range nucleon-nucleon correlations investigated in 12C(e, e'pp)10Be and 16O(e, e'pp)14C

Two-proton correlations were studied in two (e, e'pp) experiments. The first one on 12C was performed in close to 4π geometry at a beam energy Ebeam=705 MeV, an energy transfer ω = 225 MeV, and a three-momentum transfer q = 412 MeV/c. The electrons were observed in a large acceptance magnetic spectrometer in coincidence with protons detected in a BGO crystal ball. Missing energy and momentum, relative momentum and angular distributions were derived and compared with a factorized two-nucleon emission model. Soft-core Jastrow correlation functions are favoured by the data. The second experiment was a high resolution pilot study of the reaction 16O(e, e'pp)14C using three magnetic spectrometers at Ebeam = 855 MeV, ω = 215 MeV, q = 316 MeV/c. The excitation energy resolution in 14C was about 1 MeV. Two-hole states were preferentially excited in this reaction. A first comparison with unfactorized model calculations is presented. (author)