Experiment E06-007: Impulse Approximation limitations to the (e,e'p) on 208Pb, identifying correlations and relativistic effects in the nuclear medium
According to many theoretical models, a proton may, on occasion, approach another proton or neutron from across the nucleus, and the two will seem to pair up briefly before flying apart. The phenomenon, known as nucleon-nucleon correlations, is thought to be related to the force that binds protons and neutrons together into nuclei. At longer distances, the force is attractive (long-range correlations), while at closer distances, it becomes repulsive (short-range correlations); thus, the force that crushes protons and neutrons together in the nucleus is the same force that prevents the nucleus from collapsing in on itself.
Interpretations of some experimental evidence has suggested that the nucleon-nucleon correlations description is accurate. This experiment is further testing this description, as well as whether a relativistic model can more simply explain the proton's experimentally observed properties.