The large seminar room of the Physics building, Weizmann Institute of Science
"Probing repulsive core of the nucleon-nucleon interaction via the 4He(e; e'pN) triple-coincidence reaction": We studied simultaneously the 4He(e,e'p), 4He(e,e'pp) and 4He(e,e'pn) reactions at large momentum transfer, large missing momentum, and Bjorken X>1. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum leaving the residual A=2 system at low excitation energy. The measurement cover the region where the nucleon-nucleon (NN) force is expected to change from predominantly tensor to repulsive (most probably scalar). Our data are compared with calculations of two-nucleon momentum distributions in 4He and discussed in the context of probing the elusive repulsive NN force.