Nucleon-Nucleon Correlations, Short-lived Excitations, and the Quarks Within

Understand

This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon.

• We focus on the interpretation of measurements of the EMC effect for valence quarks, a reduction in the Deep Inelastic Scattering (DIS) cross-section ratios for nuclei relative to deuterium, and its possible connection to nucleon-nucleon Short-Range Correlations (SRC) in nuclei.
• Our review and new analysis (involving the amplitudes of non-nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and the effects of SRC that is not an accident.
• The influence of strongly correlated neutron-proton pairs involving highly virtual nucleons is responsible for both effects.