Do Ordinary Nuclei Contain Exotic States of Matter?

Abstract

The strongly repulsive core of the short-range nucleon-nucleon interaction leads to the existence of high-momentum nucleons in nuclei. Inclusive electron scattering can be used to probe these high-momentum nucleons and study the nature of the corresponding short-range correlations in nuclei. With recent data from Jefferson Lab we have begun to map out the strength of two-nucleon correlations in nuclei, while upcoming experiments should allow us to isolate the presence of multi-nucleon correlations. In addition to their importance in describing nuclear structure, these configurations of correlated nucleons represent high density 'droplets' of hadronic matter. As the density of hadronic matter increases there should be a weakening of quark confinement, similar to the onset of deconfinement expected at extremely high temperatures. While there have been hints of non-hadronic structure in nuclei, future measurements will allow us to directly probe the quark distributions of high density configurations in nuclei. A modified quark structure in these closely packed nucleons would provide a clear signature of exotic components to the structure of nuclei.