Speaker
Description
Short-range correlations between nucleons appear to be a universal feature of the structure of nuclei. In a short-range correlation, nucleons fluctuate to a state of very close proximity, and experience interactions that are much stronger than the typical mean-field attraction. This results in nucleons occupying states of high momentum, much larger than the nuclear Fermi momentum. Though only a fraction of nucleons participate in a correlation at any moment, correlations may play an outsized role in determining a range of important properties, including the equation of state of dense nuclear matter, the matrix elements of double beta decay, and the modification of the quark structure of bound nucleons. While much has been learned about the behavior and properties of short-range correlations from quasi-elastic electron scattering, the mechanisms that produce correlated pairs are not well understood. Recent experiments at Jefferson Lab have been conducted to study pair formation across the 1f_{7/2} shell gap by measuring quasi-elastic electron scattering from 40Ca, 48Ca, and 54Fe targets in kinematics dominated by scattering from correlated nucleons. I will present preliminary results from the CaFe Experiment, which show very little pairing of neutrons in the 1f_{7/2} shell with protons in the ``40Ca core.'' I will discuss the implications for pairing mechanisms based on angular momentum and quantum number selection rules.
